FeaturesHeavy Duty Office Chair tilt control back and forth, gas cylinder height activation,Can be twisted to tighten or loosen backward tilt tension Universal SizeTilt control mechanism fit for most chairs cylinder,is great for replacement and upgrade for almost all mesh chair, ergonomic office chair, desk chair and task chair Premium Grade ReplacementThis chair lift control give your chair , Stable use, tilt control no noise. Easy to Use twist wheel to tighten or loosen (adjust) backward tilt tension. Push lever to tilt, pull out to unlock. FunctionSingle lever for gas cylinder height activation, accepts standard 28mm inner diameter tapered gas lift cylinders. Specification: Material: Steel Size Chart: Style A: 27.8cmx17.5cm/10.94inchx6.89inch Style B: 24.7cmx17.5cm/9.72inchx6.89inch Package Includes: 1 Piece Office Chair Tilt Control Mechanism Note: Please allow slightly errors due to manual measurement and different monitors.