For instance: M4-1175-F6-D1
Denotation: 'D'; in the model number, denotes the inner diameter (ID) of the Aluminum Ring, and is the dimension where the counter hoop rim will seat. Click- How- to - Measure a Conga...
Available Crown sizes: 9.75", 10.75", 11.06", 11.25”, 11.75", 12.25”, 12.50", 13”
See illustration (A)
'D1' is the smallest and 'D4' is the largest inner diameter measurement.
The ID design accommodates the conga counter hoop rim sizes from the various manufacturers in the
industry. Click- to Find Your Model Drum
See illustration (B)
Note that the Crown Size or the playing surface remains the same on all Symmetry Conga drumheads
while the (ID) dimensions code changes