When you are in the bath for a long period of time, the cycle of water turning from comfortably warm to tepid to cold is frustrating. On rare occasions, I drain out some cold water and refilling with the warm water. Warm On pebbles look to resolve this problem innovatively. The pebbles are sensor-fitted heat-radiating artificial stones that maintain the water temperature for a set duration. So from start to finish, you can have the same water temperature without any guilt.