About Camelbak Mule: The Camelback Mule is a tried and true hydration pack in the Camelbak lineup. It's been through numerous iterations. color schemes, strap designs, you name it. You can find Camelbak Mule models dating back to 2008, which when put that way, sounds like carbon dating is involved! Well, it's survived through the years as a top-selling Camelbak because it is indeed a premier mountain bike hydration system. Not to mention, good for hiking, adventure races, you name it. When you think mule, you think stubborn. you get the idea. And that's just the point, the Camelbak Mule won't give up on you hydrating yourself, holding adequate liquid reserves for your hydration needs.