Introducing the adjustable aluminum front upper arm. A caster angle adjustment function has been added to the aluminum upper arm with high rigidity and low backlash by using duralumin material. This makes it possible to adjust the caster angle even in GALM where the caster angle is fixed. The adjustment part employs step adjustment, which is the true value of OD, and can be adjusted quickly and reliably by accessing only one screw. The adjustment pitch is 0.5mm (about 1.0 °), and it is possible to adjust with a minimum pitch that cannot be imitated. The adjustment range is 5 levels and is set to 12 ° to 8 ° when used with GALM. In addition, the camber can be easily adjusted with a 3.7mm turnbuckle wrench. Available in three colors: purple, red and black. A dedicated upper arm shaft is also available as a spare part.