What sizes does a mridangam come in?

Wesleyan's collection records two mridangam sizes. The lower-pitched taggu shell is about 61 cm long, with openings of about 17 and 20 cm; the higher-pitched hecchu shell is about 56 cm long, with openings of about 16.5 and 19 cm. A concert mridangam is tuned to the performer's tonic, and one research dataset records instruments at six tonics from B to E.