Designed for power chewers, the Sporn durable Marrow Chew Bones are nylon bones with a strong jerky flavor down the middle! As the dog chews, the nylon bristles, which acts like a toothbrush and helps remove plaque and tartar from gums and teeth. Unlike traditional rawhide bones, this is designed to last. The jerky scent never goes away and entices the dog to keep coming back for more.Please discard Chew Bone once the end knobs are chewed down. Always monitor your dog for safe chew play. Sizing and Dimensions:Small - Recommended for dogs between 10-25 pounds: 1 inch width, 4 inch heightMedium -Recommended for dogs between 25-40 pounds: 1 inch width, 5 inch heightLarge -Recommended for dogs between 40-80 pounds: 1 inch width, 7.5 inch heightX-Large -Recommended for dogs over 80 pounds: 1.5 inch width, 9 inch height