Stainless steel hybrid ceramic bearings, available as model S684C2OS (4x9x4 mm) and model S686C2OS (6x13x5 mm). Designed for speed, low friction, and low maintenance operation in small rotating equipment. Key benefits Higher speed and lower friction: Si3N4 ceramic balls reduce rolling resistance compared to allsteel bearings, improving rotational smoothness. Corrosion resistance and durability: 440C stainless steel rings provide rust prevention for use in humid or marine environments. Low maintenance: Selflubrication design requires no grease or oil, reducing upkeep and contamination risk. Contaminant protection: Orange rubber seals keep out dirt and debris while retaining the dry lubrication. Precision performance: ABEC7 (P4) tolerance ensures consistent running accuracy for sensitive or speed applications. Electrical insulation: Ceramic balls reduce electrical conductivity through the bearing when insulation is desirable. Technical specifications Models and sizes: S684C2OS 4x9x4 mm; S686C2OS 6x13x5 mm Rings material: 440C stainless steel Balls material: Si3N4 ceramic Inner diameter: 4 mm for S684, 6 mm for S686 Outer diameter: 9 mm for S684, 13 mm for S686 Width: 4 mm for S684, 5 mm for S686 Precision: ABEC7 (P4) Seal type: Orange rubber seals, double sealed Lubrication: Selflubrication, no grease or oil required Features: speed, rust prevention, dry lubrication, electrical insulation How this solves common problems Reduces downtime and maintenance by eliminating regular greasing and resisting corrosion in wet or dusty environments. Improves responsiveness and smoothness in small motors and spinning components through lower friction and tight precision. Protects delicate electronics and components by providing electrical insulation where current leakage through bearings is a concern. Typical use scenarios Fishing reels: standard bearings to reduce spool friction, resist saltwater corrosion, and extend service life without frequent relubrication. RC cars and small electric vehicles: Use in wheel hubs, transmissions, or motor shafts to improve speed, reduce heat, and lower maintenance intervals. Power tools and small motors: Install in drills, gimbals, or home appliances to achieve smoother operation, reduced vibration, and better endurance in dusty or damp conditions. Compatibility and installation notes Choose the model with matching dimensions for direct replacement: S684C2OS for 4x9x4 applications, S686C2OS for 6x13x5 applications. Doublesealed design simplifies handling during installation and reduces the need for immediate relubrication. Reliable, precision hybrid bearings for applications where speed, corrosion resistance, and low maintenance are priorities.