Slim profile is extremely useful when snowboarding in a sunny day in CA

Just what I was looking for. Arrived as advertised.

This hydration pack is perfect in every way.

Excellent for skiing and early morning skiing under jacket. Fits well no freeze issues

This pack is the ultimate low profile for carrying 50oz (1.5L). It's better than the other 50oz, such as the Hydrobak and Octane Dart, for a few reasons. Firstly, it's the most performance oriented for the 50oz thanks to the double sternum straps (the bottom one can act almost as a belt strap if brought low enough) and the double shoulder strap connection points at the bottom. This ensure that the pack is hugging you like it's part of your body, ensuring stability regardless of the level of movement, especially in the terrain park. Second, it is a dedicated low-profile pack; so for those of you thinking you can also fit a couple things, look at the Zoid instead. Therefore, you can wear this under a jacket, whether it's a snow, rain, or running jacket, and it does it well. Third, it is insulated, unlike the Hydrobak; so if you think for a second, that means it will not only keep it from freezing in the winter, but it will also keep it cool during the summer. So the insulation is actually a benefit for the warm season too. Finally, the back and shoulder materials are mesh, which allows you to stay cool even when using during the heat. Therefore, this pack excels as a dedicated low profile pack you can wear under a jacket for all seasons (not just winter) while providing the best performance stability of all the 50oz packs.