There should be more than two kinds, one is that there are central holes at both ends like ordinary workpieces, the other is that there is no central hole, and the other should be an inner circle. But it's the same. Just adjust the taper on the lower workbench. The scale above is 1, 2, 3, 4, which means 1 degree, 2 degrees, 3 degrees, 4 degrees. The general taper of 1 degree is just adjusted to 1.