I recently purchased the CellAED and the Prep Kit from LivCor. The CellAED is a great idea, but to be fully effective, the prep kit is a necessity. For example, it includes a razor to remove chest hair to ensure the device adheres well to the skin. It also includes other important items, all packaged in a convenient see through container that can be placed in a visible and easily accessible place. I had a small issue with some damage in delivery, but LivCor immediately rectified the issue with no problems. 5 stars from me!