GoLite Ion Dimensions?

Just wondering if anyone has the overall dimensions for a SMALL GoLite Ion pack.
The site lists cubic inches and states it will fit a 15 1/2 – 17 inch torso, but does not list the actual height/width/depth.

Looking for a light pack for my 7 year old son- I was planning on sewing a pack for him (adding more features and custom fitting it) but realized that the small Ion is very similar in size to what I designed, minus outer mesh pockets. Just wanted to compare.

Thanks.