Designed for micro-mechanical systems where space is at an absolute premium, the MR105-ZZ is a top-tier miniature deep groove ball bearing. Equipped with dual steel shields (ZZ), it excels at keeping dust and debris out while securely retaining its factory-filled lubricant. Because these pressed metal shields operate entirely without contacting the inner ring, the MR105-ZZ guarantees virtually zero rotational drag. This ultra-low starting torque makes it the definitive solution for high-speed 5mm shaft applications, including RC car drivetrains, precision fishing reels, and delicate measurement instruments.