Steel Help students of all ages develop better sitting habits in this ergonomic student stack chair. The seat shell vented back, and waterfall seat edge add a healthy sitting experience. Ergonomic shell seat with vented back, chrome frame, plastic floor glides Design: stacks up to 20 high, comes fully assembled to use right away Ideal environments: classroom, homeschool, library, recreation centers, after-school centers, adult education schools PRODUCT MEASUREMENTS: Overall Size: 19.5"W x 23"D x 32"H; Seat Size: 17"W x 15.75"D x 17.5"H; Back Size: 17"W x 16.5"H; No Assembly Required