Shure says that you MUST use a microscope with a least 200X magnification, and that it must have two side lights to reflect off the two sides of the stylus under examination. Also required are photos of new, worn, and extremely worn stylii of the same profile as the one you're looking at. The stereo shop where I purchased cartridges many years ago had the correct equipment. The manager of the shop also examined all new cartridges and replacement stylii to make sure that the stylus was aligned correctly on the cantilever. He found many that were misaligned, which he returned to the suppliers. His suppliers told him that he returned far more new stylii than any other retailer. Obviously, the rest of the retailers did NOT have the correct equipment and/or the experience to use it correctly.
