Master Mfg. Co Deluxe Duet Non-Hooded Chair Mat Caster Set - Includes 5 wheels and 10 stems; 5 each: 7/16" Dia. x 7/8" Long and 3/8" Dia. x 7/8" Long, 110 lbs./Caster, Matte Black Finish Nonhooded casters take the guesswork out of caster stem selection. Twin-wheel design rolls safely on hard floors and chairmats, prevents damage and minimizes runaway chairs. Durable construction supports up to 120 lb. per wheel. Casters are designed for chairs with metal bases (sold separately).