Our 10 month old British Lab Jack loves these! He has a small, and two large. We have to be really careful with what we buy him because most dog toys he can destroy in 5 minutes or less. He gets two or three Bumi in his mouth and looks like a bandit as they curve up in front of his eyes. Pretty darn funny. He shakes them like a captured prey which is our only wish about the Bumi. Jack needs one 50% larger!! We should send a video of him running crazy with a large in his mouth, shaking them against the floor. Fully recommend.