Heavy duty, high-density polyethylene material with a light grain surface. Injection molded into a one-piece shell unit with heavy duty reinforcing ribs as well as molded slots to accommodate the twin back support tubing. This design offers no exposed hardware on the surface and added strength and durability. The frame is formed of 14 gauge 1" (15 & 17 inch chairs) - 7/8" (11 & 13 inch chairs) steel tubing legs with 3/4" twin 14 gauge back supports. Legs and back are MIG welded for reinforced strength. Constructed using a cross-over leg design providing maximum support with minimum stress on welds. Bright nickel chrome plated for a durable, scratch resistant finish. Legs are swaged for added strength and a more stylish look. Chairs can be cross stacked to 25 high. The glides are silent, rubber cushioned, swivel of self-leveling, 1 minimum diameter, hard carbon steel, nylon base type with a flat bottom, chrome plated.