Urethane Round Head Dumbbell(CPU) CPU urethane Dumbbells weight head is attached to the handle with a threaded nut and welded. Chrome handles resist chipping, flaking, peeling, and corrosion. Medium grade knurling for a secure, comfortable gripping surface. Weight heads are pressed onto handle and welded. The urethane are extremely high tear strength rating. Can be resistant to tearing and damage. look and feel much smoother and are much easier to clean than rubber.