Crackle Baff crystals – it’s really fun for kids! The crystals hiss, click and change the color of the water. Slowly pour the powder into the bath and watch the water change color, the water starting to hiss and click. Along with the hiss, the water begins to change color and gives the little ones even more joy. The product is hypoallergenic, biodegradable, safe for humans and the environment. Does not stain skin and surfaces, easily cleans off the bath.