KFI Seating Kool Series Polypropylene Stack Chair with Perforated Back and Casters, Lime Green Finish Polypropylene seat and back provides durability and easy cleaning with perforated back for maximum comfort and airflow 15 gauge steel frame in a silver finish for superb stability with black non-marring floor glides help protect floors Stacks 15 high for easy storage and transportation on 2" dual wheel hooded casters Chair is weight tested to hold 400lbs Life-Time frame warranty, rated for commercial use and GSA approved