The OM5-AS Active Stacker Chair is more than a stack chair. It offers comfort, style and durability! Unstack, sit back and enjoy the fit of the OM5 Active Stacker. The chair's back flex's allowing you to sit up or recline just enough to relax. The OM5 Active Stacker features “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 feaures a 300 lb rating and is available in 8 colors, along with a wide variety of seat and back upholstery. You can order your OM5 Active Stacker with or without arms and either with a Black, Palladium Gray or Chrome base finish.