YOKOMO Aluminum Adjustable Rear "H" Arm Kit for YD-2/YD-4 (Y2-008RA) ?It is an aluminum rear suspension arm of variable length that greatly enhances the competitive power of the YD-2 / YD-4 series. Manufactured with high accuracy of Yokomo's original parts, rigidity is improved around the rear, highly effective for competition drift. The variable length suspension arm can be adjusted with a spacer that allows fine adjustment of the rear width, and it is also an effective point of adjustment of the front-rear balance of the machine, as well as change width to fit the body. ?For default width, one side is -2.0 mm from the normal without inserting the spacer at all. The set includes spacers 0.5 mm, 1.0 mm, 2.0 mm in pairs. Using the 0.5mm, 1mm, and 2mm spacer on one side can increase length to 1.5 mm from normal. Fine adjustments in as little as 0.5mm. If you add more additional spacers separately, on one side you can widen up to plus about 6 to 7 mm (Please install a long universal bone separately). Since inserting / removing the spacer is possible even with it attached to the machine, this adjustable arm can be used as a fine adjustment point during the competition. It is an item that is highly recommended for the competition drifter.