Tickit Perception Semispheres - Set Of 8 Colors - Transparent Manipulatives For Visual Sensory Play - Observe Light And Color-Mixing - Light Panel AccessorySet of 8 sensory Perception Semispheres measuring 2' dia. come in eight different clear colors and feel smooth and warm to the touch. The very youngest children will enjoy handling them in free sensory play or as part of a treasure basket collection. Older children will find them fascinating as they hold them up and look through to see the world around them in different colors. When a hemisphere is placed on top of an object it magnifies it by 4 or 5