Shadow square
| Type: | Shadow square |
| Geometry: | Box |
| (Numbering) starts at: | 0 |
| (Numbering) ends at: | 12 |
| Numbered: | every 3 |
| Repeats: | 4 times |
| Divided every: | 3 (None) |
| then every: | 1 (None) |
| Notes: | Alternanting shading distinguishes between units. |
Scale located on: Tympan, Womb or Back .
Location(s) detail:
| e: | All four sides of the shadow square, commonly found in the lower half of the center of the instrument. (e) |