The Hero Retriever Series Squeaker Bone Ball has an irregular shape for easy gripping, throwing, retrieving, and chewing. This Hero dog toy is made of natural rubber, so it rolls, bounces, and even floats. It has nubs for chewing and a built-in squeaker to add excitement. The 4.5 Hero Retriever Series Squeaker Bone Ball is super-strong, nontoxic, and dishwasher safe. Imported. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Dog Toys.