Review on Lion Locks Sliding Window and Door Locks (10 Pack), Adjustable Aluminum Security Screw Lock for 3/16-3/8” Track, Door Stopper Safety Lock, Easy Install, No-Drill Required, Requires 28-36mm Clearance for Screw Lock by Steve Hardy

Good window lock, has a rubber insert to protect the window railing. Also has two screws for better grip. The screw heads are a bit small for my hands. But they hold up well and seem to work well. As previously mentioned, it is recommended to use two locks per window, one on the bottom and one on the top. This helps with the extra security. Only give 4 starts for the somewhat small screw knobs, making it a bit difficult to get a good grip to tighten the lock. Otherwise I find it a very good lock and not expensive at all.