Batteries included?:No Product Dimensions:10 x 5 x 5 cm; 20 Grams Feature: Aluminum alloy headset top cap bike fork expander bung for 1 inch(24.5mm) or 1.25 inch(28.6mm). Replaces conventional star nut and top cap, a must for bike steerers. Can be used repeatedly, bite tight, does not hurt the fork, a must-have for top-grade bicycles. Eliminating the risk of damage and providing added support to the fragile top edge of the steerer. Just use the hexagon wrench and then you'll get it installed in minutes. Specification: Material: Aluminum Alloy Color: Black, Red, Blue, Golden (Optional) Size: Approx. 5 * 3.2 cm / 1.96 * 1.25 in Weight: Approx. 50-55g Package List: 1 * Bike Stem Headset Scope of Application: Aluminum alloy top cap bicycle fork expansion cap for 1 inch (24.5 mm) or 1.25 inch (28.6 mm). Made of quality material, which is durable, antioxidant and durable for prolonged use Best Accessory: Replaces the conventional star nut and the top cap, a must for bicycle guides. Perfect tools to help you replace your old broken piece bicycle, useful accessories for MTB, mountain bike, road bike, folding bike, etc Robust & Durable: Can be used repeatedly, biting hard, does not damage the fork, an essential element for top-notch bicycles Practical Tool: Eliminating the risk of damage and providing additional support to the fragile top edge of the address. Can firmly connect the front fork and the stem Easy Installation & Removal: Just use the hex key and then install it in minutes, convenient to install and remove Scope of Application: Aluminum alloy top cap bicycle fork expansion cap for 1 inch (24.5 mm) or 1.25 inch (28.6 mm). Made of quality material, which is durable, antioxidant and durable for prolonged use Best Accessory: Replaces the conventional star nut and the top cap, a must for bicycle guides. Perfect tools to help you replace your old broken piece bicycle, useful accessories for MTB, mountain bike, road bike, folding bike, etc Robust & Durable: Can be used repeatedly, biting hard, does not damage the fork, an essential element for top-notch bicycles Practical Tool: Eliminating the risk of damage and providing additional support to the fragile top edge of the address. Can firmly connect the front fork and the stem Easy Installation & Removal: Just use the hex key and then install it in minutes, convenient to install and remove