Description: 【High Precision Ball Bearings】: Each carrier is equipped with premium ball bearings that ensure smooth sliding and minimal resistance, providing efficient operation and stable performance 【Universal Compatibility】: Specifically designed for 1/2 inch track grooves, these carriers are versatile and can be adapted to various channels, traverse rods, and track installations, making them suitable for a wide range of projects 【Smooth and Quiet Operation】: The ball bearing design significantly reduces noise levels, ensuring a quiet glide that is ideal for environments where low noise operation is essential 【Replacement Rollers】: These heavy duty rollers serve as reliable replacements for curtain drapes, enhancing the longevity of your window hardware setup 【Ideal for Window Hardware Systems】: Perfectly suited for use in window hardware systems requiring precision and durability in their components Specification: Material: ABS Plastic Size Chart: 4cmx1.3cm/1.57inchx0.51inch Package Includes: 30 Ball Bearing Carriers Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.