"Happy Heat Bottle Collection combines a hot water bottle and heating pad: each unit targets a specific pain. The water permanently is pre-sealed, so there is no need to refill and /or to empty the water after each usage. It is a 100% natural heat treatment: there is no chemicals. Easy to use: plug the cord for 15 minutes, unplug it and the unit stay warms up to 5 hours. Happy Heat Electric Bottle stays warm longer than an ordinary hot water bottle"