The Rio is engineered for support and comfort it has enhanced ARC Technology® for improved, weight-assisted flex. It is built with an easy-grip edge that acts as a pull handle. The Plastic model 4-leg stacks 4 on the floor and 8 on the optional cart, plastic wire rod model stacks 6 on the floor and 15 on the optional cart. The Rio has an optional left or right folding tablet arm in 2 finishes. Select from 14 plastic shell colors. Choose fully upholstered, upholstered seat or plastic. All models come in 2 frame finishes with matching arm pads. The Rio has a 300 lbs. weight capacity and a Lifetime Warranty.