Review on Defender Security 9850 Housing Aluminum by Michael Clarke

which attaches to the BACK of the OUTSIDE sliding door. These door locks are available in multiple sizes to accommodate different track sizes/widths and door heights. You'll need to measure the width of the track and determine how high the pin will be at the bottom of the sliding door - you don't want to drill a hole in the glass. These dimensions are only for ordering a door lock that matches the SIZE of your door. Please note - they provide the exact dimensions of the lock in their description. TO INSTALL ON A SLIDER THAT IS INSTALLED ON THE REAR you will need to place this pin in the bottom of the track (INSIDE) and turn the handle to the left as if OPENING the door. (the pin is fully retracted), then mark the drill holes for the bottom rail so that there is approximately a 1/16 inch hole between the fully retracted pin head and the slider. Mark these holes and then pre-drill a hole in them. Key. If you drill these holes first (rather than the larger hole in the slider) you can't go wrong with that placement. Drill a larger hole in the slider AFTER you have pre-drilled these 2 holes on the bottom rail. It's the perfect low cost solution to secure our door so it can't be lifted off track. Actually we installed two.