AlphaBetter Adjustable-Height Student Stool gives students the option of swinging their legs for continuous movement, which may facilitate better breathing and lumbar support with slouch-free, "open-angled" posturing. Height adjusts in 1-1/4" increments (21-1/2" to 35-1/2") to accommodate students of all ages and sizes and so you can pair it with Safco AlphaBetter Adjustable-Height Stand-Up Desks. Welded steel frame is powder-coated for durability and features a wide-angle, tip-resistant base design for student safety. The 13" x 13" seat is made from 5/8" thick medium-density fiberboard with Thermoplastic laminate finish that is chemical-resistant and impact-resistant. Metal, swivel-glide feet allow easy movement across smooth and carpeted floors