Playology Dual layer bone, Soft and chewy on the outside, hard and durable on the inside. For moderate to heavy chewers. Chewing activates the microencapsulated scents. Cleaning Instructions: Rinse with warm water to clean. Pat dry. Dimensions: 3.5" long for dogs up to 15lbs. Safety Information: Tested to meet ASTM guidelines for safety for children's toys and the CPSIA (Consumer Product Safety Improvement Act) standards for lead, phthalates and other toxins deemed hazardous. Warning: No toy is indestructible. Toys should always be inspected regularly as any rips or tears can injure your pet. Damaged product should be taken away from your pet and disposed of immediately. Ensure the toy you select is appropriately sized for your dog. Remove and discard all packaging prior to use.