Safco Products 3420BL Trenton Extended Height Chair (Optional arms sold separately), Black Trenton drafting extended height chair Contoured waterfall seat and spring action back Features pneumatic seat height adjustment 23" to 33", 360 degree swivel, tilt adjust with tilt tension and tilt lock, back height adjustment Five star steel base with footring and 2" dual wheel hooded carpet casters Use with Safco Products optional Fixed Loop Arms Model 3497, Adjustable T-Pad arms Model 3499 and Floor Glides Model 5138, sold separately