Features: Waterproof bottom bracket nuts for mountain bikes can effectively prevent water, sand, dust, etc. from entering the bottom bracket, effectively increasing the service life of the bottom bracket. Mountain bike road bike dead-speed bottom axle steel waterproof screw, diameter 8mm, suitable for ordinary square hole bottom axle, bottom axle is not suitable, use two screws on bottom axle Specifications: Material: Steel Weight: about 13g Application: Bicycle square hole central Suitable for 8mm wrench Package Contents: screw*2 Compatibility - 2 PCS Cycle Bike Bicycle Bottom Bracket Axle Crank Bolts M8 Screw Good Performance Materials - These bike accessories are made of premium material, ensuring their durability and long-lasting performance. Optimal Performance - These accessories offer versatility and adaptability to different cycling needs and provide optimal performance and reliable functionality enhance the riding experience and ensure safety. Easy Installation - These accessories can be easily installed on your bike to get your bike running again. After-sale Serive - We provide high quality products, if there is any problem with our product, please contact us.