3D armrest and adjustable headrest offer customized comfortable support 90°~130° reclined backrest satisfies your working, reading, and napping needs Adjustable seat height (19''-23'') and seat depth(17.5''-19'') for different needs Weight activated lumbar support can bead just automatically according to the individual's weight Ergonomic backrest with independent height adjustment to free you from back pain Mesh seat and backrest for better breathability 360° smooth rolling mute casters for flexible and quiet mobility Premium class-4 gas rod ensures higher using safety Heavy duty aluminum alloy base makes it strong enough to hold up to 330lbs Assembly Video： https://www.youtube.com/watch?v=-CaWSfreqpAColor: Black Material: PP, Nylon, Metal, Mesh Overall Dimension: 28'' x 28'' x 46''-50'' (L x W x H) Adjustable Seat Height: 19''-23'' Seat Depth: 17.5''-19'' Armrest Height(from ground to armrest): 29.5''-32.5'' Net Weight: 53lbs Weight Capacity: 330lbs Package Includes: 1 x Mesh Office Chair 1 x User Guide