i thought they only came in S, M or L - I dunno to be honest - they're pretty stretchy so 1 will fit quite a lot of different horses - and I'd imagine people with big fat cobs are unlikely to be wanting an overgirth (assuming you're wanting one to go XC?) so sizes don't need to be that big.
Most TB's (who are racing) are about 195cm all the way around - don't ask my why/how I know this...but seems to be a pattern...!
