Pet Plastic Rodent Mice Jogging Hamster Gerbil Rat Play Toy Exercise Ball Brand new and high quality. Doors unlock by twisting anti-clockwise. Provides hours of active fun for your small animals. This ball allows the Hamster to mix pla and exercise,making it more enjoyable for the Hamster and more motivated to keep in good shape. This product is designed to screw-fix together which makes it stronger then conventional play balls is suitable for Hamsters,and small animals.