Elevate your mechanical applications with these precision ABEC-7 rated ball bearings. Each bearing in this 4-pack features exact dimensions of 30x40x6mm (inner x outer x width), making them ideal for applications where space is at a premium. The double rubber-sealed design effectively maintains lubrication while preventing dust and debris infiltration, ensuring consistent performance. Crafted from high-grade bearing steel, these bearings deliver smooth, high-speed operation and exceptional durability. Their thin-wall construction makes them particularly well-suited for bicycle applications and other precision machinery where compact size and reliable performance are essential. The bearings' precise engineering ensures minimal friction and consistent rotation, while the professional-grade materials provide dependable service under regular use. Perfect for maintenance, repairs, or new builds requiring precise, space-saving bearing solutions.