Recently I tossed a tonic water into a camelback and discovered that I could pressurize my hydration system... then I ran across this thread. So, I purchased an engine and a filter last week. The product was sent very fast, and the product certainly is one of the best on the market today. BTW: I entered the code and the website said it was invalid. Wrote an email as per the above post, but it was put it back on me for not entering the code even though I did. Bummer, but then again I've never even gotten an email from camelback! The hydration engine might be good enough to purchase again without the hassle of a discount/no discount code, but I have questions about the product line. Thought maybe some of those who are in the know could help: Can we get more of just the bladders? I don't need all the tubes and bulbs, just more of the bladders. I want to either use different items in the bladders (e.g., water vs sports drink, dirty vs clean water, or keep one chilling in my polar-bear cooler while drinking from another) Anyone have additional pictures of the shuttle on their bikes? Does it work well as a tank bag or primarily as a backseat bag? The bladder would be good to use as a hot pack when in a hammock (or tent) if wrapped in a towel or climashield. Can the bladder handle boiling water (or 180degree water)? There are two filters listed on the website, but one that looks replaceable cartridge says it won't be out until spring. What is the difference between the two filters? Spring 2014, or is it already available and the website needs updating? Thanks.