Please Note : Please select the appropriate joystick head size, especially the mounting thread. Steps of installation: 1.Prepare joystick head with appropriate size; 2. Remove the joystick head to be replaced; 3. Installed on the arcade game. Easy to install and replace, easy and fast to use; The surface of rocker head is smooth and beautiful; Lightweight. Joystick handle, is in size of : 40mm/1.57-inch dia, M6 thread size. The joystick head is a part of an arcade game machine. Feel comfortable and easy to operate. Rocker ball top handle is mainly used in arcade game.