This door handles can be bolted inside or locked outside Easy install: Just use screwdriver ( Not included) to install doorknobs in a few minutes Suitable door thickness: 35-50mm / 1.38-1.97inch, Adjustable door for enhances home security and styles Make of zincs alloy, strong and Enduring, fine polishing The is good for bedrooms, living room, bathrooms, hotel, let and more, Manufacturer: BULAIDAI