SAFCO PRODUCTS-CASTER,HARDFLOOR,BK. TaskMaster Hard Floor Casters, Black, 5/Set. Shown with optional Hard Floor Casters (SAF5132), sold separately. Pneumatically adjusts 8" up or down while seated. Overall height adjusts 19" to 27". Contoured, black polyurethane self-skinning foam seat and back won’t crack or peel with wear. Large nylon reinforced base with 20" diameter chrome-plated adjustable footring and 2" high-impact nylon-reinforced glides. Backrest adjusts 3" in height and depth. Seat: 16-1/4w x 16-1/4d. Stem Type: N/A; Wheel Tread: N/A; Color(s): Black; Material(s): N/A.