Kelty Tumbler 30/50 Review Kelty is a American Recreation Products company and manufacturers of high-end backpacks, tents, and sleeping bags. Kelty Tumbler collection offers three different sleeping bags for different temperature ranges. The Kelty Tumbler 30/50 is the warmest member of the Tumbler collection. Functionality: The Kelty Tumbler series includes external snaps and liner loops [...]