Here's what other sites are saying:
You never want to lose water on the road or during an expedition, which is why it helps to have the MSR In-Line Shut-Off Valve. With a low-profile design and tough HDPE material, this valve is easy to use and extremely convenient from long treks in the backcountry to cycling races in town. It fits most hydration systems and packs thanks to its in-line style, and it has a sleek and lightweight construction so it resists snagging and dripping.
MSR Camp & Hike In-line Shutoff Valve 6699. Compatible with any Platypus BigZip SL and Hoser and MSR Hydromedary hydration reservoirs.
Current Retail: $4.49-$5.95
Historic Range: $4.49-$5.95
Where to Buy
Yeti Rambler Tumbler Straw Lid
Guyot Designs SplashGuard
Platypus Bite Valve Cover
Nalgene Insulated Water Bottle Sleeve
$10 - $17
Platypus Bite Valve and Drink Tube Insulator
$13 - $15
Nalgene Easy Sipper