Tilt & Lock -Lever: push in or pull out to lock or unlock -Knob: increase or decrease the force needed Adjustable Tilt Tension Proper seat depth is vital for optimal seated comfort, blood flow to lower legs and minimal pressure on soft tissue. Breathable Mesh Back and Seat This mesh office chair has been designed to prevent body heat and moisture build up. The breathable mesh fabric seat provides ample padding for all day comfort. Ergonomic Design The human ergonomic design back naturally fit the human body with back curve. You will not feel tired even sit for a long time. Seat Height (cm)：38 - 48 Seat Width & Depth (cm)：50 x 51 Armrest Height (cm)：58 - 68 Back Width & Height (cm)：45 x 66 Gross Weight (kg)：13.3 Standard：BIFMA & BS5852 5 Star Leg's Material：Metal Back Material：Mesh Thickness of Seat：8 cm Weight Capacity：264 lbs / 120 kgs Assembly instructions：Self Assembly