The sensory rollers from Fat Brain Toys are made with high quality, BPA-free silicone that is safe for teething. Ever one of the sets has three beautifully textured spheres. They have chimes inside. The hidden chimes sing with every movement. The spheres are in the colors blue, green, and orange and each one of them measures 2.5 inches in diameter. Every sphere has two different textures which means that baby gets a total of six textures. Sensory Rollers from Fat Brain Toys encourage cause-effect learning, creativity, and sensory exploration. They enliven baby’s sensory play. The Sensory Rollers are dishwasher safe.