Alvin - Premo - Ergonomic Task Chair - Black - Ergonomic features in a rugged contemporary design, the Premo from Alvin is the ultimate in seating comfort at a reasonable price. Backrest provides solid orthopedic spine support and full-size upholstered seat is contoured for added comfort. Features include pneumatic height control, polypropylene seat and back shells, a heightand depth-adjustable backrest with heavy-duty spring tension angle control, dual-wheel casters and a 25 inch diameter reinforced nylon base. Seat cushion is 19w x 17d x 3 thick. Backrest is 16w x 14h x 2+ thick. Office model height adjusts from 16+ to 21+. Drafting model includes CK49 height extension kit and adjusts from 24 to 29. Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.