Enduro R8 2Rs Enduro Max Cartridge, Id=1/2" Od=1-1/8" W=5/16" ID=1/2" OD=1-1/8" W=5/16" Commonly used for hubs and suspension pivots Known usages include Spinergy and Santa Cruz Dual-lip labyrinth seals keep dirt out and grease in More balls without retainers for increased load capacity