The OM5-AC Active Cafe? Stool is a blend of comfort, style and durability. Comes in 2 heights and available with a book tray and arms. The OM5 Active Cafe feature “body-activated motion” inspired by a desire to create responsive ergonomic seating through precise engineering which responds automatically to changes in body position. The chair features a 300 lb rating and is available in 7 colors, along with a wide variety of seat and back upholstery. You can order your OM5 Active Stack with or without arms. We love the fit and feel of the OM5 Active and so will you!