Bi Pointed Stylus (BPS33),
which was NOT available for more than 40 years!!!
You can play a vinyl stamper directly on a regular turntable, to check the sound and stamper quality, before you start pressing your vinyl records. To play the negative of a vinyl record, a stamper stylus is a must for EVERY vinyl pressing plant or broker! Avoid mastering and pre-mastering errors before you start production, so there will be NO unwanted scrap.