Using animated LED lights under the skin, your students will see the effect their CPR Compression Depth, Speed and Recoil has as the red LED lights respond to the quality of their technique. This essential visual learning tool instantly reinforces CPR Trainers instructions to students. The Brayden’s dual modes help structure CPR training: from learning effective CPR to perfecting CPR technique. 6 “C” alkaline batteries can power 160,000 compressions.