I extensively research everything before I buy it, so it's no surprise I rate almost everything highly. This is no exception. From reading the other reviews, I determined that the SMALL cover was adequate for my Maxpedition Kodiak, and it fits well. Also, it fits the somewhat larger pack http://www.amazon.com/Fieldline-Tactical-Alpha-Internal-Backpack/dp/B00AN0RXOI/ref=sr_1_1?ie=UTF8&qid=1357329950&sr=8-1&keywords=fieldline+alpha+ops perfectly. I'm going to order another one of these in Small for that pack as well. I can't imaging carrying a pack requiring size Large in this raincover. They are definitely over-sized from what you'd expect.