Lot of 2 E-MTB Chain Guide Pulley Assembly Sprocket, Bolt, Guide Sealed BearingsI bought these from Alta Cycling Group they distribute and Manufacture IZIP, Raleigh and Haibike's.This is the descripition they used:PULLEY ASSY 17,18 ds emtb SPROCKET, BOLT, & GUIDESprocket: Steel 14 toothBolt Length: 53mm total lengthBolt diameter: 9.85mmWeight: 121gThis is for a lot of 2 of these Pulley wheels