6300 Series Height Adjustable HD Square Seat Steel Stool with Back, Supports Up to 500 lb, 18"-26" Seat Height, Brown/Gray Features a square, contoured hardboard seat with 16 rivets. Sturdy 0.88" O.D. 18-gauge steel tubing. The 0.63" O.D. foot rings are welded to each leg by four contact points for added rigidity. Backrest adjusts up/down and forward/back. Leg height adjustable in 1" increments up to eight additional inches. Tested by Bureau Veritas to support 500 lbs static load capacity.