NOT STANDARD DIMENSION - (8.6 inch x 6 inch wide) with 1.1 inch hole diameter and 2.5 mm thickness - mechanism features. Turn the steering wheel to tighten or loosen (adjust) the forward backward tilt tension and move the arm for height. Fits for the majority of gas cylinders. It is IMPORTANT to measure your mounting hole dimensions before ordering. NOT STANDARD SIZE, check with picture. OFFICE CHAIR MECHANISM REPLACEMENT LETS YOU RESTORE YOUR OLD CHAIR AND SAVE MONEY - Is your favorite office chair in good shape? Use this basic office chair replacement part to make your chair like new again quickly and effortlessly. If you're unsure about the gas cylinder, you can also replace it with a 5-6 inch gas cylinder. Measure your old piece first; other sizes are available to avoid an unnecessary return. EASY DISASSEMBLY AND ASSEMBLY - Clear step-by-step photo instructions are provided on the listing page, so even a non-professional can install this chair mechanism. Everything you need is included with the purchase, so replacement is hassle-free. It is much more environmentally friendly, economical, and satisfying to repair your favorite office or gaming chair. SUPERIOR QUALITY REPLACEMENT MECHANISM - A new mechanism that fits most gaming chairs, executive chairs, and office swivel chairs. It is important to measure the dimensions of your mounting hole before ordering. This heavy-duty tilt control mechanism withstands a weight of up to 450 lbs. Enjoy quiet rotation on your office swivel chair. Also fits gas cylinder and many other chair types. Color: black Material: metal Package Contents: 1 x office chair mechanism Only the above package content is included; other products are not included. Note: Light and different displays may cause the color of the item in the picture to appear slightly different from the real thing. The measurement allowed error is +/- 1-3 cm.