K9 Sport Sack Dog Carrier Booster Block, Medium/Large

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At a Glance

  • No Assembly Required
  • All Lifestages
$12.95 Chewy Price
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About This Item

Details

  • Specially designed to fit snuggly at the bottom of the K9 Sport Sack Air Forward Facing Backpack Dog Carrier.
  • Adds 3 ½ inches of height so your pooch can sit more comfortably in the backpack.
  • Built out of high-quality foam so it can stand up to heavy-duty use through walks, bike rides, rucking sessions and more.
  • Comes with a removable cloth with zipper so you can keep it nice and clean for your pup.
  • Great for dogs who are in between the available pack sizes, including shorter dogs, growing pups or canines who are short and stout.

Instructions

Size

FAQ

Learn More About K9 Sport Sack From Our Team of Experts

Questions & Answers

3 Customer Questions

What is the weight of this booster block?

Does this fit in the plus 2?

Answer by Chewy • Aug 23, 2025
This booster block is specially designed to fit snugly at the bottom of the K9 Sport Sack Air Forward Facing Backpack Dog Carrier.

so if i move to colorado or north carolina will my dog be able to be in here he is a 6.5 yorkie and he gets travel sickness

Answer by Chewy • May 15, 2018
The Booster Block and Carrier are designed for all small and medium breeds. We recommend measuring your dog to find the best size to choose for them.
Reviews
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4.8
Rated 4.8 out of 5 stars
17 Ratings
Terms & Conditions

9 Customer Reviews

Rated 5 out of 5 stars
By Faron on May 15, 2025

Perfect for existing backpack

I have a mini dachshund and a medium bag gifted to us, this block fit perfectly for my dog.

I have a mini dachshund and a medium bag gifted to us, this block fit perfectly for my dog.

Rated 3 out of 5 stars
By Dani on Sep 17, 2023
Top 1000 Contibutor

Booster is tad big for a medium backpack

The item itself is wonderful but the size is a bit off. To support the bottom of my medium backpack, I had to really push it in and it was awkward there and I could

The item itself is wonderful but the size is a bit off. To support the bottom of my medium backpack, I had to really push it in and it was awkward there and I could feel it on my back. I’m thinking small could have been better.

Rated 5 out of 5 stars
By Victoria on Dec 27, 2023

Sport Sak review

Very helpful esp if your dog is between a large carry sack or a mefium

Very helpful esp if your dog is between a large carry sack or a mefium

Rated 5 out of 5 stars
By Laura on Nov 10, 2022

Perfect Fit

Works great with this backpack. Keeps my Italian Greyhound mix from having to stand on her toes to look over my husband's shoulders. Good fit for all of us.

Works great with this backpack. Keeps my Italian Greyhound mix from having to stand on her toes to look over my husband's shoulders. Good fit for all of us.

Rated 5 out of 5 stars
By Mona on May 27, 2022

It works like a champ!

We tried a small and she couldn’t fit into it and then a medium and she still didn’t fit so I purchased this block and now she fits! I’m really happy!

We tried a small and she couldn’t fit into it and then a medium and she still didn’t fit so I purchased this block and now she fits! I’m really happy!

Rated 5 out of 5 stars
By SJBern on Apr 10, 2018

Very comfy

Makes the K9 Sport Sack very comfortable for my miniature poodle.

Makes the K9 Sport Sack very comfortable for my miniature poodle.

Rated 5 out of 5 stars
By Jill on Mar 6, 2018
Top 50 Contributor

I didn't use it for the knapsack

I put 3 of these in a pillow cover. My newest kitty is an adult but very tiny (he was a stray so maybe stunted growth?). I wanted a thick foam but not one he would

I put 3 of these in a pillow cover. My newest kitty is an adult but very tiny (he was a stray so maybe stunted growth?). I wanted a thick foam but not one he would sink into. My other cats can sit in their room and look out the window. He couldn't. ..till now.

Rated 5 out of 5 stars
By Carrier on Feb 3, 2018

Don't leave without me

I'm glad that I got the booster for fozzie so that he would have leverage while sitting in the sport sack. He still has a lot of room inside the sack.

I'm glad that I got the booster for fozzie so that he would have leverage while sitting in the sport sack. He still has a lot of room inside the sack.

Rated 5 out of 5 stars
By hugo on Nov 12, 2017

Good for the bag

Bought the bag a little big since my dog is still growing, this booster makes him fit in it. I recommend just getting the booster instead of using a rolled up towel,

Bought the bag a little big since my dog is still growing, this booster makes him fit in it. I recommend just getting the booster instead of using a rolled up towel, since the booster fits so much better.