Heavy, with annoying plastic tag
At first my cat was very interested in the fun movement of these whizzing along the floor, but the balls are deceptively heavy and so you need to be careful. My poor girl took a bop to the head and now the mere sight of them brings a play session to an immediate end. So they've gone in the cupboard. Better to roll them along the floor. Oh and there is an annoying plastic tag in each of them that you just can't quite remove, so they stick out slightly sharply.