Mountain Hardwear Down Bag Expander

It works just like the description said it would.
The Mountain Hardware Down Bag Expander zipped in easily. When I used it, it gave me (6'3" 210 lbs.) enough more room in my mummy bag to sleep comfortably without feeling claustrophobic. Now, I'm looking forward to using my mummmy bag instead of dreading it.

Worked Great
The only reason, I give it a 4 is that it states 8" of girth. I expected 8 inches the length of the bag. This expander tapers down from 8". I zipped this in my North Face Blue Kazoo mummy bag and it fit with about 4 " of extra. Still added much needed room. (6'2 230 lbs)