RPM's Traxxas Nitro Rustler, Nitro Stampede, & Nitro Sport A-arms are built to stand up against the toughest abuse from the backyard basher all the way to the top-level racers. A-arms incorporate all stock geometry; yet have been redesigned for strength, looks, performance, and durability. RPM build these A-arms from our well-known trademark blend of nylons for bulletproof performance and unsurpassed durability. They carry our reputable warranty against breakage as well. These A-arm sets are sold in pairs and come in either black or our extremely popular blue, which is molded into the A-arm for scratch resistant color that lasts and lasts.