When it comes to bags of all types Dakine always seem to be on the mark and it's certainly the case with the Glacier hydration pack. It's made from hard-wearing nylon and houses a 70oz bladder in its main compartment.
This is attached to a drinking tube neatly threaded through the shoulder strap so you can tuck it away so it's not flapping while you're riding - always a good thing if you're freeriding or downhilling. Also, this is a winter pack, so if you use it for snowboarding the water won't end up freezing in the tube.
The shoulder straps are well padded and the pack is kept in place with both waist and chest belts so it doesn't move about as you ride. There's an elastic bungy strap on the front to keep things clamped down and rattle-free and there's a zip pocket for your important stuff like keys and cash. The pack is on the small side so it's not meant for big epics but it's perfect for day rides, shuttle runs or freeriding.