While most hydration packs could be used for just about anything, they're typically designed with activities like mountain biking or running in mind. The Duet, on the other hand, was created specifically for use at outdoor music festivals.
Currently the subject of a Kickstarter campaign, the Duet is made by Chicago-based startup Grasshopper Gear.
First and foremost, the pack features a screw-cap 3-liter reservoir for keeping users hydrated while dancing under the beating sun. It also has two quick-access chest pockets in front, for easily grabbing items such as smartphones. Given the fact that some festivals don't allow multi-pocketed hydration packs, however, the chest pockets can be temporarily detached and stored inside the main compartment while going through security.
Particularly precious items like wallets can be stashed in a zippered anti-theft pocket which sits against the wearer's lower back. Extra clothing such as jackets, on the other hand, get stuffed beneath bungee cords on the back of the pack. There's additional storage space in the main compartment, alongside the reservoir.
It should be noted that the zippers of the chest pockets and main compartment are kept closed with clips, making it more difficult for thieves to quickly and surreptitiously open them.
Should you be interested, a pledge of US$79 will get you a Duet hydration pack of your own – the planned retail price is $135.
The pack is demonstrated in the video below.
Sources: Kickstarter, Grasshopper Gear