This is the best sleeping bag for our 35 pound dog (Size M) we’ve been able to find. I used the Noble Camper riding from San Francisco to Portland. This sleeping bag was in her carrier on the bike and became her bed in the tent. Only recommendation for improvement is the filling. Possibly a 800-fill water-resistant DriDown? If the interior were packed more the shape would be better retained/add more padding/comfort, but weight is the consideration as well. Awesome overall!