This gear knob only fits automatic transmission with press down release button, easy to install and disassemble. It is a nice automobile accessory for car. Features: Made of high-quality aluminum with lightweight carbon steel, durable to use. Black simple design, provides an elegant and fashionable driving environment. This gear knob can recover the performing as well as you used to and better for racing. Easy to install and disassemble. If you can't install, please find a professional installation. Comes with 3 adapters different sizes ( 12mm . 10mm , 8mm ). Specifications: Material: Aluminum Color: Black Package Weight: 180g / 6.35ounces Package Size: 120 * 50 * 50mm / 4.72 * 1.97 * 1.97in Installation Instructions: Remove existing knob. Select correct adapter and install over it. Slide knob on to shaft , make sure release button works. Tighten down with 3 set screws. Packing List: 1 * Gear Knob 3 * Adapters (Length: 38mm ; Inside Diameter: 8/10/12mm ; Outside Diameter: 15mm) 4 * Black Screws (Size: 5mm ; diameter: 4mm) 1 * Wrench (Size: 51*17mm; Opposite Sides: 2mm)