TremShield white window restrictor cable lock with release key and mounting screws
Window restrictor cable

Window Restrictor Lock

4.6 · 5 reviews

Opens for air. Stops at a few inches.

$19.99One-time · free tracked shipping
Free tracked shipping Free 30-day returns 1-year warranty
  • Limits how far a window opensA steel cable lets it vent, then stops it short.
  • A short reach, a clear limitToo narrow to reach far into. Not a tested child-safety device.
  • Key release for cleaningUnlocks fully for washing the glass or a wide-open day.
  • Screws on in minutesA small bracket on the frame and the sash, that is it.
Window Restrictor Lock $19.99

Two risks, one window

An upstairs window is two risks in one.

Open it for air and an upper-floor window becomes an entry point off a porch roof or a ladder. Keep it shut and the room turns stuffy.

A restrictor settles both. A short steel cable lets the window vent a few inches and no more, so air moves and a reach-in stays short. A key releases it fully whenever you need the window wide.

The same few inches that cool a room keep a reach-in short.
4in
vent gap
1key
full release
5min
to fit
2styles
casement and sash
White window restrictor with a chrome key lock, its steel cable holding a white casement window open a few inches
Air without the worry

A few inches of breeze, and a hard stop.

The cable holds the window to a set opening, enough to move air through a room without leaving a gap someone could reach far through.

Turn the key and the cable releases, so the window opens fully for cleaning or a warm day. Because it takes a key, keep it off any window a sleeping room relies on for escape.

Upstairs windowsApartmentsRentals
A few minutes with a screwdriver

Two brackets, one cable.

1

Mark the spots

Hold the brackets on the frame and the opening sash, level with each other.

2

Screw them on

Fix both brackets with the included screws.

3

Clip the cable

Attach the steel cable between them to set the vent limit.

4

Test and key it

Open the window to the stop, then check the key releases it fully.

No app, no power, no monthly fee. A mechanical limit that just holds.
For upstairs rooms and renters

Fresh air for the rooms above the ground floor.

It mounts with a few small screws that patch over easily, so it suits a rental, and it gives a window that breathes without becoming an easy reach from outside.

Layer your defense

A limited window, and an alarm on the glass.

The restrictor holds the window to a short gap. The TremShield Alarm sticks to the same pane and sounds at 125dB the second the glass is struck or pried.

See the alarm
White TremShield vibration sensor alarm
Good to know

Questions, answered calmly

To a vent of roughly four inches, enough for airflow but too narrow to reach far through. The key releases it for full opening.

No. It limits how far the window opens, but it is not a tested fall-prevention device and it releases with a key. For a child's bedroom, use a tested window opening control device that releases from inside without a key.

Only if that room has another way out. An escape window has to open from inside by feel, without a key, and this one takes a key. Fit it on windows nobody sleeps behind.

It works on most opening windows, including casement and sliding sash styles. The brackets mount on the frame and the moving part of the window.

It fixes with a few small screws. The holes are minor and patch over easily, which makes it workable in most rentals.
White TremShield vibration sensor alarm with red indicator light on a white background
Pairs with this

Add the alarm layer.

A lock slows a break-in down. An alarm makes sure it never stays quiet: the TremShield Vibration Alarm senses the first vibration and answers with 125 dB, before a window ever gives. Peel-and-stick install, no Wi-Fi, no monthly fees.

From $29.99 · six for $99, or $16.50 each

See the Alarm

From the security guide

How to Sleep with the Window Open (Without Leaving It Open to Anyone)

A window at night is shut and locked, or open and held. Set a four-inch gap with a lock that holds it, put the alarm on the pane, and sle...

Read the guide →

Stay one step ahead

Real home-security tips, first looks at new gear, and the occasional subscriber-only deal. Unsubscribe anytime.