Probe large bores and deep features—these Renishaw styli have a contact surface that’s 1.5x the size of that on our largest ball styli. When they touch a workpiece, they trigger your coordinate measuring machine (CMM) probe to send a signal and measure geometric features. The size of the half ball keeps the stem from accidentally touching your part, preventing your probe from falsely triggering and measuring inaccurately. It also evens out the inconsistencies from measuring rough and textured surfaces, making these styli a good choice for use on threads. To minimize their weight, the half ball is hollow and made of lightweight ceramic.