Series Inner Diameter Structure 61800 10 - 320 mm Z, ZZ, RZ, 2RZ 61900 10 - 280 mm Z, ZZ, RZ, 2RZ, N, NR, ZN, RZN 16000 10 - 260 mm ?/TD> 6000 10 - 260 mm Z, ZZ, RZ, 2RZ, RS1, 2RS1, N, NR, ZN, RZN 6200 10 - 220 mm Z, ZZ, RZ, 2RZ, RS1, 2RS2, N, NR, ZN, RZN 6300 10 - 190 mm Z, ZZ, RZ, 2RZ, RS1, 2RS3, N, NR, ZN, RZN 6400 10 - 100 mm N, NR Miniature bearings 1 - 10 mm Z, ZZ, RS, 2RS