The print requires 4 (8-32 x 1 1/2 inch ) screws . Make sure they come with the nuts your local hardware store will have them. I tested using screws and nuts from lowes. I created this outlet with toddlers in mind. I have a toddler myself and for the life of me i could not stop him from messing with the outlets in my living room. I tried the outlet covers from walmart, lowes, home depot, and others i found online. I couldnt find one strong enough to keep him out so i designed this one. I have printed and tested this myself and he is still yet to be able to get into it. The ones you buy elsewhere only use the middle screw of the outlet cover and hold together with tabs which are very weak. If a child pulls from the top or bottom of a regular safety outlet with enough force they could easily break it. With this one i have added top and bottom screw holes so you can use the top and bottom screws that hold your actual outlet into the recepticle box. Because of this design with the 3 screws into the outlet itself it makes my outlet cover very strong and almost completely unpenetrable. I made the outer box part of the outlet so it has 4 screws, 2 on top and 2 on bottom that secure it all together. On the outlet plate itself it has 4 squares with slits in them to insert a nut in each which when you put it together the 2 holes on top and two holes on bottom line up perfectly with the 4 nuts and make it a very strong enclosure. I also put 2 holes in the bottom of the enclosure that perfectly fit 2 plugged in cords securely so even if your toddler or person pulls on the cords they will not break the enclosure. This design could also work for mentally disabled people, autistic children, or any troubled individual you need to keep protected from an exposed outlet.