HP-F17 Ambulance Chair Stretcher Stair Stretcher Emergency Folding Rescue Stretcher)The main material is high strength aluminum alloy which is hardened and surface treated. 2)Stretcher surface is sewn by high density polyethylene coating nylon material. 3)This stretcher can be transformed into chair mode. It adopts 125mm wheels, which can move in narrow aisles and areas that are difficult to go through. 4)When in chair mode, the height of the chair backrest is 125cm, and the seat is 50cm. 5)Fold able support and the casters all