Each model comprises a measuring head, a set of extension rods and a spacing collar to facilitate alternative measuring ranges.
The smaller models (901, 902 & 903) have detachable extension handles.
| 901 | 1-2 | 0.0001 | 0.25 | POA |
| 902 | 2-8 | 0.0001 | 0.50 | POA |
| 903 | 2-12 | 0.0001 | 0.50 | POA |