Replacement Office Chair Tilt Control Seat Mechanism w/ 4" x 7" Mounting Holes- S4264 Replacement office chair tilt mechanism with 3.8" wide x 7.2" long screw mounting hole pattern Single lever for gas cylinder height activation - Accepts standard tapered gas lift cylinders Tilt control - push lever in to lock tilt, pull out to unlock Twist hand wheel to tighten or loosen (adjust) backward tilt tension Black