Offering enrichment by helping satisfy dogs’ instinctual needs, the KONG Classic’s unique natural red rubber formula is ultra-durable with an erratic bounce that is ideal for dogs that like to chew while also fulfilling a dog’s need to play. Want to extend play time? Be sure to stuff with tempting bits of kibble and entice with a dash of peanut butter. Add to the fun by adding KONG Snacks and topping with KONG Easy Treat. Mentally stimulating toy; offering enrichment by helping satisfy dogs’ instinctual needs KONG classic red rubber formula for average chewers Unpredictable bounce for games of fetch Great for stuffing with KONG Easy Treat; Snacks or Ziggies Recommended by veterinarians and trainers worldwide Natural rubber Made in the USA. Globally Sourced Materials.