Flexi-Felt 6502 Caster Cover, box of 250 covers fit standard plastic desk chair casters that are 2-1/8 to 2-3/8 inch diameter. Use 2 covers per dual-wheel caster. Box of qty 250 Flexi Felt Caster Covers will outfit 25 typical rolling desk chairs or stools when each has a 5-prong base. Caster covers are clear to blend easily with chair casters. The 6502 Flexi-Felt Caster Cover is a larger size diameter and fits easily over the chair caster then heat to form to wheels. If this size is too big for the dimension of your caster-based chair or stool, the smaller diameter 6501 Caster Cover may be a better fit. Number of chairs each package will outfit depends upon the number of casters on each chair or stool.