KD, Executive Arm Chair Swivel Adjustable Height: Lant 60mm Gas lift (Class Two By Sgs Certificated) Back Tilt Mechanism: Multi-functional mechanism could lock the back tilt position, provides a knob for the tension adjustment (Seat Angle 1-14 Degree) Padded Back & Seat: Black PU 5-Star Base w/Casters: 350mm (Radius) Powder Coating Base With Nylon Caster Armrest: Black Padded & Silver Powder Coating