I used mohair girths for a long time before switching to the woolback ones
with double elastic. I'm actually considering getting elastic put on my
old mohair girths, giving me the coolness of mohair with the expandability of
the elastic ends. I ALWAYS looked for 100% mohair, nothing
synthetic. For me it was because Cheers would blister with synthetic
girths or pads, but I really believe the 100% mohair is the best you can
buy.