1.Middle back office chair. 2.Mesh Fabric upholstered. 3.Aluminum leg. 4.Tilt,swivel,up and down ,lock at any position office boss chair/mesh fabric executive chair.middle back swivel chairmaterial: mesh fabric upholstered, mesh fabric back.aluminum leg. High and direction adjustable armrests.function: tilt,swivel,up and down ,lock at any position