This is a pack of four optional Avid RC 12mm Spring Collar Adapters. These 12mm Spring Collar Adapters are machined from billet 6061-T6 aluminum alloy and black anodized, while the 4-40 x 1/16" stainless steel set screws give that premium look. These collars are used by sliding them over your stock Team Associated collars and securing them in place with the included stainless steel set screws. With these adapters you will be able to run the 12mm Avid Springs or Team Associated 12mm Big Bore Springs on your standard Team Associated shocks. Part# AV1014