ERGONOMIC: This set of 4 ergonomic mesh back office chairs fits the bill if you're seeking exceptional seating comfort for multiple employees SAFETY & COMFORT: Ventilated curved mesh back with built-in lumbar support prevents overheating; 3" padded waterfall seat relieves pressure from the legs while providing cushioning for long workdays HIGHLY CUSTOMIZABLE: Pneumatic height adjustable 360 degree swivel seat; Tilt lever - push in to lock in an upright position; pullout to activate rocking motion; Tilt tension knob controls tilt resistance; Functional flip-up arms allow ease of access ASSEMBLY & CARE: Each Chair Assembles in 30 Minutes or Less; Clean with Solvent Based Cleaner PRODUCT MEASUREMENTS (4): Overall Size: 24.5"W x 25.5"D x 37.5-41.25"H; Seat Size: 20.25"W x 19"D x 17.25-20.75"H; Back Size: 17-20"W x 23"H; Arm Size: 26.25-30.25"H from floor; 8"H from seat