This heavy-duty toy is crafted with a new advanced natural rubber material for extra long-lasting play. Mammoth Tirebiter toys are sustainably manufactured in a North American factory and proudly designed and developed in the USA with USA materials. Designed with a progressive chew system, which means pups will slowly start to gain strength as they work their way up in toy size! Roll, toss or tug the tire to encourage interactive play and keep your canine companion engaged and encourage healthy exercise. Available with knotted rope for tugging and additional texture and enjoyment, or without for pure chewing enjoyment.