Great stretch means that three sizes will fit all:
S for extra small to small
M for sizes medium to large
L for sizes extra large and extra extra large
Small / S
Arm Length 47cm | Bicep 30cm
Medium / M
Arm Length 48cm | Bicep 32cm
Large / L
Arm Length 49cm | Bicep 34cm
Extra Large / XL
Arm Length 50cm | Bicep 36cm
Double Extra Large / 2XL
Arm Length 51cm | Bicep 38cm