These Straps are used for the TGR-Arm Training Aid:
SMALL - (10" length) suitable for children and those with smaller arms.
MEDIUM - suitable for juniors and adults. Strap is 14" long and is the same size as the strap included with the TGT-Arm unit.
LARGE - This optional strap for the TGT-Arm is a larger size (17" length) suitable for adults with larger arms.