Bat Warmer II is the same Battery operated, high quality insulated nylon material as the original. We made it to easily attach to your bags, or be tucked into the bags till you get to your game. Designed by a professional to help protect those expensive bats from breaking, while letting you hit like its the middle of summer. (DOES NOT FIT THE NEWER 2 PIECE BIG BARREL BATS) We recommend the original full length for them. Comes with a 2 year free heater replacement warranty, Battery is Included, and shipping is free.