Arm cylinder seal kits are composed of two main components: the seal itself and the seal housing. The seal is made from a rubber material and is usually shaped in an oval or circular shape. The seal housing is a metal cylinder that is attached to the arm or shaft of the device. When the arm is turned, the seal is compressed against the sides of the housing, creating a seal that prevents air, liquids, or other materials from entering or leaking out. The seal also prevents dirt, dust, and other particles from entering the device.