Lengthed Assistance Arm The Helper Assist Arm can swivel 180 degrees, which makes it easy to maneuver around the tire and get the right angle for mounting or dismounting it. Installation Pads This assistance arm can be used on tire changers with square post. The provided screws and pad is fit for 4.72 x (4.33-5.12) inch 120x(110-130)mm Square Post. In addition, if you have DIY skills, you can also apply this on colomn type tire changers. Dual Function The pressing tool is made of high quality hardened plastic material, which can not only press the rim of the tire but also lift one side of the tire to do tire changing. Max Stroke:355mm/13.98inch The assistance arm has vertical movement distance of 0-345mm/13.98inch. Operation Panel The switch is used to control the shaft by toggling the switch up or down. Quick Connection The assistance arm has a 8mm three-way air inlet adapter, making the connection of tire changer and assistance arm more fast and handy.