BOSS Office Furniture HIGH BACK VINYL OXBLOOD CHAIR High back executive chair with deep button-tufted back cushions. Provides look of elegance with traditional styling. . Large 27" nylon base for greater stability. Hooded double wheel casters. Upright locking position. Pneumatic gas lift seat height adjustment. Adjustable tilt tension control.Optional knee-tilt mechanism available model (B8502). Available in two upholstery choices: Black LeatherPlus.(BK) or Oxblood vinyl upholstery (BY).