Material and construction: Precisionmade metal construction provides stable performance and durability for longterm use. Sealing hardware: Includes waterproof screws that reinforce the seal between the center axle and the bicycle frame, reducing the risk of moisture and contaminants entering the joint. Waterproof protection: Waterproof design helps prevent water from reaching the bearing, contributing to extended service life of the assembly. Compatibility: Suitable for road bikes, mountain bikes, and folding bikes. Use scenario 1: Use while riding in rain or through wet, muddy conditions to protect bearings and extend component life. Use scenario 2: During regular maintenance or after washing the bike, the waterproof seal helps maintain reliable sealing around the center axle. Use scenario 3: Applicable across different bike types (road, mountain, folding) to ensure durable performance in diverse riding environments.