Ten SMR104ZZ stainless steel ball bearings 4x10x4 mm are ABEC7 precision, double shielded bearings supplied as a 10 piece pack (DDL1040ZZ). Designed for compact, precision rotation, these bearings offer dependable performance in small assemblies and hobby projects. Key benefits precision operation: ABEC7 tolerance provides smooth, consistent rotation for precise motion in tight spaces. Durable stainless steel: Corrosion resistance and long service life in varied environments. Low maintenance shielding: Double shielded design helps keep out dust and moisture while preserving lubricant. Compact and versatile: 4x10x4 mm size fits small shafts and compact mechanisms, enabling lightweight, efficient design. Readytouse 10pack: Ideal for projects with multiple bearing points and interchangeable parts. Key attributes Model: SMR104ZZ Size: 4x10x4 mm (bore x outer diameter x width) Material: Stainless steel Type: Ball bearing Shielding: Double shielded (ZZ) Precision: ABEC7 Quantity: 10 pieces Alternative code: DDL1040ZZ Compatibility and use cases Shaft compatibility: Designed to fit 4 mm shafts common in micro motors, small gearboxes, and compact robotic joints. Electronics and hobby projects: Suitable for RC micro models, small robotics builds, and precision assemblies where tight tolerances and durability are required. 3D printer and light mechanical assemblies: Can be used in small idlers, drive mechanisms, and lowload linear motion components where compact bearings are needed. Application examples Micro DC motor assemblies or gearboxes in RC toys and robotics projects requiring reliable, lowfriction rotation. Small robotic joints or couplings that use 4 mm shafts, delivering smooth motion with protection from contaminants due to double shielding. Compact linear motion components or idler wheels in 3D printer assemblies or other precision machines that benefit from ABEC7 accuracy and stainless steel durability. Installation and care tips Inspect bearings before installation for any damage; handle carefully to avoid nicking the races. Maintain shields in place to protect internal surfaces; avoid contamination from dust and moisture. Use appropriate mounting accuracy to prevent uneven load and excessive runout. If lubrication is required, use suitable lubricants compatible with stainless steel bearings and shielded designs; otherwise these bearings are ready for use in standard operating conditions. Store in a dry environment to preserve corrosion resistance and bearing performance. This 10piece pack provides a reliable source of 4x10x4 mm stainless steel bearings with ABEC7 precision and dual shielding, suitable for a range of compact applications that demand consistent, longlasting performance.