REPLACEMENT TRACKBALL - Designed for any trackball mice using 1.34 (34mm) trackball size; Such as from Perixx: PERIMICE-517, PERIMICE-717, PERIMICE-520, PERIMICE-720, Logitech: MX Ergo, M570, M575 Cordless (not include Trackman Marble), Elecom: M-XT3DRBK (EX-6), M-DT2URBK, EX-G/DEFT Sanwa: MA-WTB43BK | BASEBALL DESIGN - The novelty design of baseball on the trackball. The quality and unique design of your favorite sports can be felt on your finger tip, and it provide a fun and different desktop space for yourself. This is also a perfect gift for your love one who likes the baseball and a good hobby collection. | GLOSSY FINISH - The glossy surface is treated with a special coating to provide a precise and smooth tracking performance; The matte coating trackball specializes in precise pointing and movement, ideal for long documents, excel, and handling of mass data processing. | ABSOLUTE SPHERICAL - A diameter of 1.34 inches; Provides fast movements and works perfectly for multiple screen control | HOW TO REMOVE THE TRACKBALL - The trackball from PERIMICE-517/717 and other compatible model can be easily removed from the bottom hole of the mouse, using the tip of your finger or a pencil. If the initial tracking is not smooth, you may rub the trackball to move the wax protection for the first use.