Show your dog the ropes. Strong, safe and helps clean teeth and gums. I love to floss my teeth. It's great fun because I get to chew, play, fetch and tug while helping to remove plaque. If only our owners could enjoy flossing this much. - Castor the Dog. Red Rover Rope Tugs with tennis balls are made from high density all cotton ropes with a flossy web to help reduce plaque. They're also machine washable. As with all natural cotton products, it's normal to see color and texture variations in your rope toy. Each safe and durable tennis ball is puncture resistant and non-toxic too. No humans were harmed in the production of this product. Cotton made in USA. Tennis ball made in China.