Pro-Lok - Window Lock – Single Wing Nut

It's made for both metal and vinyl horizontal sliding windows. The lock body is aluminum with a steel thumbscrew, and it clamps to the window track rather than fastening into the frame, so the frame material only has to be a standard sliding track. No drilling into vinyl required.

Yes. You position the lock anywhere along the track where you want the sash to stop, then tighten the wing nut. Set it a few inches back from closed and the window vents but cannot be slid open further; set it at the closed position and you get full security. That's the main reason property managers pick this style over a fixed keyed sash lock.

No. This lock is built for horizontal sliding windows, where it clamps into the slide track. A double-hung sash moves vertically and a casement swings out on a crank, so neither has the horizontal track this lock needs. For those you want a sash lock or a casement window latch instead.

No fasteners into the sash or frame. The lock mounts onto the bottom or top of the window track in the position you choose and is secured by tightening the wing nut against the track. That makes it removable and repositionable, which is useful in rentals where you can't modify the window.

Pro-Lok lists it for residential, commercial and industrial use. It's a heavy-duty aluminum body with a steel thumbscrew, not a plastic consumer clip, so it holds up in multi-family and light commercial turnover work where the same part gets specified across a lot of openings.

The single wing nut version uses one steel thumbscrew to clamp the lock in the track, which is enough for most sliding windows and is quicker to set and reset when you're adjusting the vent position. A two-screw version spreads the clamping load over a longer footprint, which matters on wider or heavier sliders. If you're locking standard residential or light commercial sliders, the single is the simpler choice.

Aluminum is the only finish offered, which is the natural finish of the lock body itself. It sits in the track rather than on the face of the window, so it stays visually out of the way regardless of the frame color.