When you are in for a long soak, the cycle of water turning from comfortably warm to tepid to cold is frustrating. On rare occasions I indulge in draining out some cold and refilling with the warm water. But my eco-conscious mind chides me for it! Anyways, 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. Awesome!