What this product solves Prevents water and dust from reaching the bearings by improving the seal at the middle axle connection, reducing corrosion and wear and helping extend the service life of moving parts. Improves ride stability and power transfer through a tight mechanical interface between the part and the bicycle base. Key features and benefits Includes mixing screws: delivered with mixing screws to improve the seal between the middle axle and the bicycle frame, effectively blocking water ingress. Waterproof and dust-resistant function: designed to keep moisture and particles out of bearings and other internal components, prolonging component life and reducing maintenance frequency. Square-hole interface: features a square hole that connects securely to the bicycle base, increasing stability and transmission efficiency for smoother, more reliable pedaling. Compatible with multiple bike types: suitable for road bikes, mountain bikes, and folding bikes—provides a consistent, stable, and smooth riding experience across these models. Performance and practical advantages Reduces bearing contamination to maintain smooth rotation and lower friction. Enhances drivetrain stability by ensuring a tight mechanical fit at the axle interface. Lowers long-term maintenance needs by keeping contaminants out of critical moving parts. Typical use scenarios Commuting in wet conditions: helps prevent water from entering bearings during rainy rides, minimizing the risk of rust and premature failure. Off-road or muddy trails: reduces dust and grit penetration in mountain biking applications to maintain bearing performance and reduce service intervals. Travel with folding bikes: maintains a secure, stable connection and protects internal components while folding and unfolding or during transport. Compatibility and fit notes Designed for use where a sealed connection between the middle axle and bicycle base is required; applicable to road, mountain, and folding bicycles. Comes complete with mixing screws to assist installation and improve the axle-to-frame seal. Practical considerations Improves longevity and reliability of bearing assemblies without changing standard riding characteristics. Simple to integrate into compatible bicycle assemblies; follow installation guidance for correct tightening of mixing screws to achieve optimal sealing. This product focuses on sealing, protection, and mechanical stability—key attributes for cyclists who want to reduce maintenance and preserve drivetrain performance in varied riding conditions.