Endoskel Baseball Catchers Thumb Guard: Right Hand Thrower or Left Hand Thrower. Made with Military Grade Aircraft Aluminum & Xtreme Impact Protection Foam Technology THE TERMINATOR OF ALL CATCHERS THUMB GUARDS! With Extreme Impact Protection open cell foam technology, reduces thumb joint flexion & pain from ball impact. Gives you more control and more glove closing power. Stays in the glove, does not fall out. No need to insert it or remove it from the glove during a game. It's not worn on the hand. Search Endoskel on Youtube see how it works. The Power and Strength of MILITARY GRADE AIRCRAFT ALUMINUM, It's Not Just for Baseball Bats.