Heavy Duty Office Chair Tilt Control for back and forth movement, with gas cylinder height adjustment. Features a twist wheel to tighten or loosen backward tilt tension. Universal Size Tilt Control Mechanism fits most chair cylinders, ideal for replacement or upgrade on mesh chairs, ergonomic office chairs, desk chairs, and task chairs. Premium Grade Replacement Chair Lift Control provides stable performance and smooth, quiet tilt function. Easy to Use: Adjust tilt tension with the twist wheel. Push lever to recline, pull out to unlock. Function: Single lever controls gas cylinder height adjustment. Compatible with standard 28mm inner diameter tapered gas lift cylinders. Specification: Material: Steel Size Chart: Style A: 27.8cm x 17.5cm / 10.94 inch x 6.89 inch Style B: 24.7cm x 17.5cm / 9.72 inch x 6.89 inch Package Includes: 1 Piece Office Chair Tilt Control Mechanism Note: Please allow slight measurement variations due to manual measuring and different display monitors.