K9 Sport Sack

K9 Sport Sack Dog Carrier Backpack Booster Block


HUMPHREY SAYS: Are you in between sizes and need an extra boost? Designed for pups that are shorter and wider. Try the booster block in your K9 Sport Sack backpack for an instant 3" boost.

PLEASE NOTE: K9 Sport Sack items are shipped directly from the brand, therefore can only be exchanged, and are non-refundable. K9 Sport Sack items cannot be shipped outside the United States.


  • Adds 3 inches to any K9 Sport Sack Dog Carrier
  • Made from quality foam, and built to last.
  • Removable and washable cloth cover
  • Works great for French bulldogs or other dogs that are shorter and wide
  • In between sizes in the K9 Sport Sack backpacks? Size up in the backpack and add a booster block
  • You can add up to 2 booster blocks (6 inches) in your K9 Sport Sack backpack

      SIZE & FIT:

      • XS/S are interchangeable between XS and S sized backpacks
      • M/L are interchangeable between M and L sized backpacks
      Tutorial: How to Measure Your Dog for the K9 Sport Sack