Made of plastic material, durable and lightweight For use with the complete queen rearing kit Easy to use Material: Plastic Quantity: 20 pcs Package Contents: 20 x Cell Fixtures 20 x Roller Cages 20 x Cell Cup Holder Color: Transparent+Black+Yellow Total length: Approx. 76mm Outer diameter: Approx. 26mm Internal diameter: Approx. 18 and 24mm Size: Approx. 25x21mm Note:Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.