Pick the Dolly Replacement Caster to meet your needs. Good replacement casters for plastic, steel, aluminum, or wood dollies, as well as other applications. Choose from economical polyolefin to the higher quality Resilex™ with footbrake and total lock brake. All are non-marking. Models 72724 and 72725 have slotted holes that measure 1-3/4x2-7/8" centers. Model 72732 is sold in packages of 4.