Fixing is very easy as they are surface fixed with screws to the frame of the door. They have one strap shaped liked a letter L.
Sold in pairs and supplied with fixing screws.

• Overall Size: 83mm x 73mm
• L Fixing Plate: 83mm x 51mm
• Finish: Black
• Dimensions: 3 1/4inch x 2 3/4inch (82mm x 70mm)