Prime-Line F 2588 Window Lock
The Prime-Line F 2588 is positioned as a best-in-class, low-cost hardware window lock for retrofit projects thanks to its simple, durable construction and wide compatibility with common single- and double-hung windows. Compared with heavier security devices on this list (like the Master Lock security bar) it delivers a strong technical value for homeowners and property managers seeking a quick, budget-friendly upgrade without sacrificing basic forced-entry resistance.
Simple slide — ninja quiet
Low-profile style — shy but strong
Simple slide — ninja quiet
Low-profile style — shy but strong
Review Summary
"Budget-friendly and easy to install; works well on many sash windows but finish and long-term durability can be hit-or-miss."
Installs fast — drama-free
Zinc die-cast construction provides corrosion resistance and everyday durability.
Installs fast — drama-free
Zinc die-cast construction provides corrosion resistance and everyday durability.
Increased Safety & Security
Aesthetic & Personal Appeal
Time-Saving Convenience
The Prime-Line F 2588 is positioned as a best-in-class, low-cost hardware window lock for retrofit projects thanks to its simple, durable construction and wide compatibility with common single- and double-hung windows. Compared with heavier security devices on this list (like the Master Lock security bar) it delivers a strong technical value for homeowners and property managers seeking a quick, budget-friendly upgrade without sacrificing basic forced-entry resistance.
Simple slide — ninja quiet
Low-profile style — shy but strong
Installs fast — drama-free
Zinc die-cast construction provides corrosion resistance and everyday durability.
Designed as a direct replacement for common sash/window applications for easy compatibility.
Simple slide — ninja quiet
Low-profile style — shy but strong
Installs fast — drama-free
Zinc die-cast construction provides corrosion resistance and everyday durability.
Designed as a direct replacement for common sash/window applications for easy compatibility.
Master Lock 265DCCSEN Dual Function Security Bar
The Master Lock 265DCCSEN Dual Function Security Bar stands out as a market leader by combining a visible, high-strength deterrent with dual-mode use for both windows and doors, offering superior forced-entry protection over compact sash or sliding locks. While it carries a higher price and bulk compared with trim locks (Prime-Line, Defender), its technical robustness and versatility make it the preferred choice where maximizing security — rather than minimizing cost or footprint — is the priority.
Dual-purpose bar — double duty hero
Adjustable length — one-size flex
Dual-purpose bar — double duty hero
Adjustable length — one-size flex
Review Summary
"Heavy-duty, versatile security bar that adds noticeable resistance to forced entry for sliding doors and windows; some users find it bulky and tricky to fit in tight spaces."
Heavy-duty steel — tank tough
Telescoping heavy-gauge steel bar adjusts to fit a wide range of window and sliding door widths.
Heavy-duty steel — tank tough
Telescoping heavy-gauge steel bar adjusts to fit a wide range of window and sliding door widths.
Increased Safety & Security
Reduced Stress & Anxiety
Time-Saving Convenience
The Master Lock 265DCCSEN Dual Function Security Bar stands out as a market leader by combining a visible, high-strength deterrent with dual-mode use for both windows and doors, offering superior forced-entry protection over compact sash or sliding locks. While it carries a higher price and bulk compared with trim locks (Prime-Line, Defender), its technical robustness and versatility make it the preferred choice where maximizing security — rather than minimizing cost or footprint — is the priority.
Dual-purpose bar — double duty hero
Adjustable length — one-size flex
Heavy-duty steel — tank tough
Telescoping heavy-gauge steel bar adjusts to fit a wide range of window and sliding door widths.
Dual-function design secures both windows and doors for versatile use around the home.
Dual-purpose bar — double duty hero
Adjustable length — one-size flex
Heavy-duty steel — tank tough
Telescoping heavy-gauge steel bar adjusts to fit a wide range of window and sliding door widths.
Dual-function design secures both windows and doors for versatile use around the home.
Defender Security U 9809 Sliding Window Lock
The Defender Security U 9809 sliding window lock is engineered specifically for sliding windows and brings an effective, low-profile solution that beats generic sash locks on fit and ease of installation for that use case. Financially more affordable than full-sized security bars and technically better matched to sliding-glass vulnerabilities than broad-use locks (like some Prime-Line models), it is an attractive option for renters and homeowners who need discreet, purpose-built protection.
Compact design — barely there
Keyed lock — parent peace
Compact design — barely there
Keyed lock — parent peace
Review Summary
"Sturdy, compact lock that secures sliding windows reliably and is straightforward to install, though alignment and screw quality draw occasional complaints."
Tamper-resistant — stubborn to thieves
Low-profile locking design clamps or screws into track to stop sash movement effectively.
Tamper-resistant — stubborn to thieves
Low-profile locking design clamps or screws into track to stop sash movement effectively.
Increased Safety & Security
Reduced Stress & Anxiety
The Defender Security U 9809 sliding window lock is engineered specifically for sliding windows and brings an effective, low-profile solution that beats generic sash locks on fit and ease of installation for that use case. Financially more affordable than full-sized security bars and technically better matched to sliding-glass vulnerabilities than broad-use locks (like some Prime-Line models), it is an attractive option for renters and homeowners who need discreet, purpose-built protection.
Compact design — barely there
Keyed lock — parent peace
Tamper-resistant — stubborn to thieves
Low-profile locking design clamps or screws into track to stop sash movement effectively.
Compact footprint keeps sightlines clear while improving sliding window security.
Compact design — barely there
Keyed lock — parent peace
Tamper-resistant — stubborn to thieves
Low-profile locking design clamps or screws into track to stop sash movement effectively.
Compact footprint keeps sightlines clear while improving sliding window security.
$12-25 CAD
Prime-Line U 9945 Sash Lock
The Prime-Line U 9945 sash lock is a compact, economical choice optimized for double-hung windows, offering straightforward installation and reliable mechanical engagement that outperforms many childproof designs in sheer holding strength. Compared with the bulkier Master Lock bar it sacrifices deterrence visibility but wins on price and ease of retrofit, making it a practical pick for large-scale or budget-conscious window security upgrades.
Classic sash look — vintage vibe
Sturdy latch — firm hold
Classic sash look — vintage vibe
Sturdy latch — firm hold
Review Summary
"Affordable sash lock that's simple to fit and works for many double-hung windows, but some users report loose fit and cheaper materials over time."
Quick mount — screwdriver-friendly
Classic sash-lock mechanism provides reliable latching for double-hung windows.
Quick mount — screwdriver-friendly
Classic sash-lock mechanism provides reliable latching for double-hung windows.
Increased Safety & Security
Aesthetic & Personal Appeal
Time-Saving Convenience
The Prime-Line U 9945 sash lock is a compact, economical choice optimized for double-hung windows, offering straightforward installation and reliable mechanical engagement that outperforms many childproof designs in sheer holding strength. Compared with the bulkier Master Lock bar it sacrifices deterrence visibility but wins on price and ease of retrofit, making it a practical pick for large-scale or budget-conscious window security upgrades.
Classic sash look — vintage vibe
Sturdy latch — firm hold
Quick mount — screwdriver-friendly
Classic sash-lock mechanism provides reliable latching for double-hung windows.
Durable metal construction replaces worn original hardware without modifying the frame.
Classic sash look — vintage vibe
Sturdy latch — firm hold
Quick mount — screwdriver-friendly
Classic sash-lock mechanism provides reliable latching for double-hung windows.
Durable metal construction replaces worn original hardware without modifying the frame.
Safety 1st ProGrade Window Lock
The Safety 1st ProGrade Window Lock is tailored for child-safety and family use, prioritizing simple operation, tamper resistance, and a modest price point over heavy-duty forced-entry protection. It compares favorably to heavier commercial locks by offering lower cost and easier removal for caretakers, but is intentionally less robust than the Master Lock or some Prime-Line metal hardware — making it best where preventing child access is the primary concern rather than stopping determined intruders.
Childproof design — parent-approved
Tool-free install — instant secure
Childproof design — parent-approved
Tool-free install — instant secure
Review Summary
"Designed for child safety, it's easy to use and prevents window opening effectively; a few buyers report breakage or fit issues on older or nonstandard windows."
Durable plastic — tough but gentle
Designed specifically to limit window opening and reduce fall risk for children.
Durable plastic — tough but gentle
Designed specifically to limit window opening and reduce fall risk for children.
Increased Safety & Security
Reduced Stress & Anxiety
The Safety 1st ProGrade Window Lock is tailored for child-safety and family use, prioritizing simple operation, tamper resistance, and a modest price point over heavy-duty forced-entry protection. It compares favorably to heavier commercial locks by offering lower cost and easier removal for caretakers, but is intentionally less robust than the Master Lock or some Prime-Line metal hardware — making it best where preventing child access is the primary concern rather than stopping determined intruders.
Childproof design — parent-approved
Tool-free install — instant secure
Durable plastic — tough but gentle
Designed specifically to limit window opening and reduce fall risk for children.
Tool-free adjustment lets adults set an opening limit while preventing easy tampering by kids.
Childproof design — parent-approved
Tool-free install — instant secure
Durable plastic — tough but gentle
Designed specifically to limit window opening and reduce fall risk for children.
Tool-free adjustment lets adults set an opening limit while preventing easy tampering by kids.