The comfortable rolling swivel stool features a thick cushioned seat with a mechanism (seat plate) screwed which can rotate 360-degree freely, equipped with a sturdy hydraulic gas lift cylinder to adjust height(height range 8”), a heavy duty 5-legged metal chrome base with durable wheel casters which can roll smoothly and swivel 360-degree .The hard-working stool chair makes it easier to get through a busy day, very convenient for multi-tasking work. The contemporary style is applicable to home and workplaces. Specifications: Upholstery: high quality thickened PVC leather Cushion: brand new high-density sponge Base diameter:20.5 inches Base material: Heavy duty reinforced aluminum Seat diameter:13.5 inches Seat height: from 22 to 30 inches Stool height(with backrest):32 to 40 inches Height range 8 inches! Caster Wheels:2.5” in diameter durable polyurethane Weight capacity: 400 lbs Warranty: 1 Year Caution: Remove the plastic cap on the top of the gas lift before assembly! This is a part of packaging only! Customer service: Please contact Shenzhen Karrie for any issues.Customer service and technique support can be provided. We welcome and appreciate customer's valuable suggestion too.