Moore and Wright Micrometer Ball Attachment can be fitted to the anvil or spindle on external micrometer series 1961, 1965 and 1966 to enable round or irregular surfaces to be measured.
Note: Always deduct the ball diameter from any reading.
| 878M | 6.5mm and 6.8mm | 6.5 ball | 1 of each spindle size supplied | |
| 878 | 0.256" and 0.268" | 0.250 ball | 1 of each spindle size supplied |
