[Size]: Cylinder: 18mm x 35mm, panel: 26 mm x 53 mm, anti-collision panel: 34mm x 53mm. [Material]: The ball door bumper is made of stainless steel and brass, sturdy and durable, anti-rust and anti-corrosion. [Adjustable]: Adjust the appropriate distance by adjusting the distance between the ball bearing lock and the deflector. Lasting tension maintains spring rebound. [Application]: Adjustable ball bearing latches for internal french doors The wardrobe is suitable for all kinds of invisible doors, cabinet doors, flat doors, wall cabinet doors, etc. [Installation]: Equipped with screws, the ball retainer is installed on the top of the inner door, which is recessed into the drilled hole on the top surface. The strike plate is mounted on the door frame and the spring loaded ball locks and holds the door closed. package: Pack of 2 ball door buckles note: Manual measurement, the size has slight errors. installation: 1. Place the locking latch in the center of the edge of the door. Mark and drill a hole 20mm in diameter and 30mm in diameter. 2. Position the clip in the hole, mark the shape of the screw hole and the board. Remove the lock, drill the screw and the chisel plate. Secure with screws. A. Locate the firing pin on the door frame to line it up with the ball catcher (the curved edge is facing out). Mark the screw hole and the shape of the contact.