Sizing your dog for a K9 Sport Sack isn't an exact science. If your dog is in between sizes, has a wide body but short in length, or is still growing, the Booster Block fits snuggly in the bottom of your K9 Sport Sack to boost your dog up 3 inches. It helps make the K9 Sport Sack experience more comfortable for you and your dog.

Features

• Constructed of quality foam
• Removable and washable cloth cover
• Two blocks may be used to lift up to 6 inches

Sizing

• XS/S are interchangeable between XS and S sized backpacks
• M/L are interchangeable between M and L sized backpacks
• XL backpacks require an XL Booster Block