Extra Battery Life
This thing is amazing if you want to extend your battery life so you don't have to swap out batteries every 1 1/2 hours or so. I recorded 11GB at 1080p at 60fps with just one battery and the Bacpak which was awesome while canyoneering! I would highly recommend this product to everyone with a HERO3. Be sure to update to the latest firmware. My friend didn't update his firmware and his HERO3 would freeze half the time when his bacpak was on.