A replacement trackball for your trackball mouse with a 1.34-inch diameter. The ball was made of high-quality material designed for major mouse brands in the market. Fits to trackball devices below: PERIMICE-517, PERIMICE-717, PERIMICE-520, PERIMICE-720,MX Ergo, M570, Cordless, TrackMan Wheel (not include Trackman Marble), M-DT2URBK, MA-WTB43BK, and more. Specifications: Diameter: 1.34-inch (34 mm) Weight: 0.06 lb (0.03 kg) Color: Glossy Lavender.