Another tried and tested favourite here at Your Whole Dog!
Here's what KONG has to say about their KONG Classic:
It is the gold standard of dog toys and has become the staple for dogs around the world for over forty years. 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.
At YWD I generally stuff them and freeze them
Check the size chart to guide your selection.