Impressive above average slider lock. Installed at the top of the door, the silver one I got should secure door in 2 directions, prevents uplift and slide. If you need directions for this install, you shouldn't be attempting the install. From safety standpoint, I drilled into metal at the very end past the estimated border of the glass pane inserted into the mullion, and ensuring plenty of clearance from glass edge. Make sure of this because I speak from experience after just nicking the glass in a past install, the entire massive pane of glass exploded per safety glass design into a billion tiny cubelets of glass and a heavy shop vac load afterwards. Easy install of simple 2 hex screws requiring a long tip marker, a drill and 2 different quality bits, (dewalt or Milwaukee) and ideally a punch tool. no directions needed, just be careful Drilling into the sliders aluminum frame required my using a spring loaded punch to establish a pinpoint dent for starting point. This will keep your drill not only on exact center but also from travelling. Choose a drill bit that when lined up with the hex screw, the diameter of the bit is roughly the same diameter as the screw but the screw is a hair wider, that is, the threads of the screw should extend just past the edges of the drill bit on both sides of the drill bit. The big hole that receives the bolt is more forgiving in tolerances, and in my case I was able to make the hole uing a paddle bit since I was now drilling into wood. I blew off trying to use the included spring loaded bolt receiving cup insert. Tight fit and secure. Bought mainly to keep the wolves at bay, meaning deter desperate future thieves from lifting door out of its track.