See: AVID RC

AVID have introduced new titanium slipper screw for the Team Associated B6.1, B6.1D, T6.1, and SC6.1. The slipper screw is made from billet 6Al-4V titanium and designed to reduce rotating mass, nearly 50% lighter than the kit steel screw. The slipper screw comes pre-pinned so you don’t lose the first pin instantly and a spare is included.