| 33 / | HD | GEOMETRICAL INSTRUMENTS |
| 501 | DF | GAUGE {61} |
| 501.05 | DF | .~ Comparator {3} |
| 501.08 | DF | .~.~ Hand held {2} |
| 501.09 | | .~.~.~ Plural contact probes {4} |
| 501.1 | DF | .~.~.~.~> Only three probes {1} |
| 501.3 | DF | .~.~.~.~> Only four probes |
| 501.4 | DF | .~.~.~.~> With rotary indicator |
| 501.45 | DF | .~.~.~.~> Fixed size |