The stool boasts a ratchet system which allows the backrest/armrest to be easily moved across the seat.This ergonomics design make it ideal for a range of users. PU LeatherThis chair is made out of PU leather, high density rebound foam inside, and superior injection plastic board underneath that ensure the seat cushion more comfortable and durable. Moreover, it is easy for maintenance and cleaning.Height & Rotation AdjustmentBoasting an adjustable height that ranges from 18.9" to 24.4", 360 degrees swing around backrest/armrest, this chair ensures that you will find the position that best suits your body type to keep yourself in an easeful place. Aluminum Alloy BaseConstructed with aluminum alloy forming die-casting feet, wide and sturdy five-star base makes the drafting stool more stable when you swivel a full 360 degrees. Equipped with a thicken high polished aluminum ring, it also can fit your height to keep your legs in an easeful place. Mute PU CastersEquipped with five PU casters, they boast good toughness, and won't scratch the floor. The upgrade wheels let out a smaller noise while sliding, and the abrasive resistance also can be better. The 360° rotating wheels can cooperate your work and let you feel free to do whatever you want. Wide ApplicationThe adjustable medical stool is ideal for hospital, laboratory, the busy medical office, spa, classroom, dorm room or home.SpecificationBackrest: 21.3" L (54 cm) Diameter of Cushion: 16.1" (41 cm) Backrest Height Adjustment: 3.9" Diameter of Foot Ring: 15.4" (39 cm) Diameter of Caster: 2" (50mm) Diameter of Five Star Base: 22.8" (58 cm) Packing Size: 20.8" L x 20.8" W x 9.0" H (53 x 53 x 23 cm) Package Content1 x Dental Medical Assistant Chair 10 x PU Casters