This is probably our best arm strengthening product and not many people know about it. Astros pitching coordinator, Dewey Robinson, says "The Fast Arm is the best warm-up, arm motion training, and arm strengthening product I've ever seen or used." We've seen immense improvement in arm strength, mechanics and velocity after using the Fast Arm for 6 weeks. In fact, we GUARANTEE you'll be throwing harder with better mechanics or we'll send your money back! Usually ships in 7-10 days.