【FIT IN 34MM TRACKBALL MOUSE】- This replacement ball is designed for any trackball mouse using a 34mm/1.34 inch trackball. Compatible with models like MX Ergo, M 570; SANWA GMATB128BK, GMAWTB129BK, GMABTTB130BK, GMATB167, GMAWTB168, GMABTTB169, GMATB155, GMATB44BKN/RN, GMABTTB1BK; ELECOM: EX-G Pro(M-XPT1MRXBK), DEFT(M-DT2DRBK-G), Kensington: Pro Fit Ergo(K75326WW), Perixx: Perimice-517, PERIPRO-801, Perimice-717, PERIMICE-520W, etc. | 【WORK WITH OPTICAL SENSORS】-This replacement trackball provides excellent optical sensors sensitivity. Comfortable for finger control and ensures a smooth & agile movement. Specialized in precise pointing, multi-screen work, file works, excel, data processing, and efficiency improvement. | 【HOW TO REMOVE THE BALL】- This SANWA trackball replacement can be easily removed from the mouse bottom using your finger or a pen. | 【GLOSSY RED COLOR】- Its surface is painted with a scratch-resistant coating and glossy red color for more effortless optical identification and smooth movement. Works Temperature: -40℃ to 60℃. | 【QUICK CLEANING TIPS】- This mouse ball replacement part is simple to clean. Either use a soft brush or a lint-free fabric. Before replacement, we suggest that you can clean the inside ball hole to avoid possible erratic cursor movement.