Berlin Modisch Heavy Duty Front Door Entry Handle and Deadbolt Lock Set - Slim Square Single Cylinder Deadbolt with Reversible Lever for Right/Left Handed Doors - Oil Rubbed Bronze Finish - Perfect for Home Security and Entryway Upgrade

This unit is easy to use. However, if you have someone in the home who struggles with either visual impairment or hand dexterity and lacks the coordination to perform multiple step tasks with their hands, make sure to try and place the unit with the center screw and see if the person can release it and open the unit easily. If they are unable to easily open this unit with practice and in adequate light, you certainly don't want them struggling to open the door under emergency circumstances or while under pressure in poor light conditions. PIf the door you are going to place this on is a typical "Right Hand Door", this means when facing the door from the outside, the hinge is on the right hand side of the door and the door would swing into the building. Since this device installs on the interior door jamb, the device actually slides to the left to release and then pivots on the hinge to the right to swing out of the way of the door. Just make anyone who would need to open the door for safe exit or entry can operate this device. It's not complicated, but it can require the door to be pushed in slightly to release the pressure which might be against the device when properly installed.You certainly wouldn't want someone trapped inside and unable to open the door because they lack the eye hand function or coordination / dexterity to safely open the door.I bought two of these and installed one 14" down from the top of the door and the second one was positioned so the bottom is 14" from the floor. These two add a lot of holding power to the door and it adds to the lock and handle which should be holding the door already.I like the fact the unit is self contained and swings out of the way when the door is opened. Once the door is closed, you simply swing the unit over the door and slide it till it snaps towards the jamb. The design of the cam provides the snap movement which both secures the unit when its holding the door closed and when its pivoted out of the way when the door is open.I like the design and concept of these. Simple and one unit. I looked at others where you have to remove a piece for the unit to open and then store the piece until needed to lock the door again. While that unit does provide storage of the removed piece, this unit is all one piece and stays together. It's just a matter of swinging it into place to secure the door or swinging it onto the door jamb side to open the door.Personally, I would install these in pairs on any door as I did. Ideally, if you maintain the same distance between the door lock and handle and each of these units, one towards the top of the door and the other towards the bottom of the door, then this should provide help in securing the door.Simple and should be effective. Would this stop someone who was determined to get through the door? It should help deter them at a minimum. Having them is certainly better than not having them.........You might have to mortise the door jamb to recess the unit's plate so the door will clear. With the door closed and standing inside, see if the units install plate with the screw holes will slide between the door and jamb opening. Chances are that it will. If you can not get the unit between the jamb and door when the door is closed, you certainly will have to mortise the door jamb. This means cutting out enough of the wood to allow you to mount the unit flush with the door jamb. It's easiest to mortise the door jamb with a small wood chisel and a hammer. There are You Tube video's to show you how to cut a mortise into a door frame.Whether you have to mortise the jamb or mount the unit flush, make sure to position it so the door is flush shut with the unit against the inside of the door. Install the center temporary screw and see if you can release and secure the device and open and close the door. Once fitted in place, install the other screws and try the unit again. It's really that simple.