【High-Quality Steel Construction for Low Noise and Long Service Life】These ball bearings are made of high-quality steel material, providing a low noise and long service life. The construction ensures that these bearings can handle various applications while maintaining optimal performance. 【Miniature Skateboard Bearings for 25mm Shaft/Rod Projects】Measuring 25mm inner diameter, 37mm outer diameter, and 7mm thickness, these ball bearings are perfect for small hobbyist projects, especially those utilizing 25mm shaft/rod projects. They are compact, durable, and efficient to allow smooth in any application. 【Compact and Durable】Despite their small size, these ball bearings are built to last. They feature a sturdy construction that can withstand the rigors of daily use and provide in even the most extreme environments. 【Rubber Sealed to Prevent Contaminants and Save Lubricant】These miniature bearings are rubber sealed, keeping out contaminants and preventing them from entering the ball bearings. The sealed design also helps save lubricant, ensuring optimal lubrication and for an extended period of time. 【Ideal for a Variety of Projects】This pack of 5 miniature ball bearings provides you with versatile and cost-effective solutions, allowing you to use them in a variety of projects, including skateboards, linear ball bearings, ceramic ZrO2 ball bearings, and more. Their high-quality construction and rubber-sealed design make them an excellent choice for a range of applications., Weight: 0.2425084882 pounds, Manufacturer: Akozon