Sturdy all-plastic construction. Fits inside all standard bathtubs and showers. 21" width x 18" depth x 29 7/8" height (top of back). Distance from outside of legs is 16 7/8", inside is 12 1/4", legs 2 3/8" Each leg adjusts seat height from 16" to 21". No tools required for assembly or height adjustments! Non-slip rubber tips on legs. Weight capacity 400 lbs.