Medical Dental Stool Dentist Chair with 360 Degree Rotation Armrest PU Leather Assistant Stool Chair Height Adjustable Doctor Chair Ergonomics Design PU Leather Height & Rotation Adjustment Aluminum Alloy Base Mute PU Casters Wide Application Diameter of Foot Ring: 15.4" (39 cm),Diameter of Five Star Base: 22.8" (58 cm),Diameter of Caster: 2" (50mm),Diameter of Cushion: 16.1" (41 cm),Backrest: 21.3" L (54 cm),Backrest Height Adjustment: 3.9",Packing Size: 20.8" L x 20.8" W x 9.0" H (53 x 53 x 23 cm)