Day-use backpacks certainly are handy, but they do have a way of leaving your back hot and sweaty, or even digging into it if you're carrying protruding cargo. The VentaPak was designed to address those problems.
Created by New-York-City-based entrepreneur Mark Dingle, the VentaPak is basically a polyester wide-mesh screen mounted on a rectangular aluminum frame that's coated in soft, squishy neoprene foam. Utilizing its integrated clips, buckles and adjustable-length straps, the device is attached to the back (i.e: the side that faces the wearer's back) of a third-party backpack.
The main idea behind the thing is that it will create an air space between the main backpack and the user, keeping their back cool and dry while also stopping non-flat objects in the pack from jabbing into them. The latter attribute is particularly applicable to cyclists, whose backs are arched into their backpack while they ride.
Additionally, however, Dingle claims that the VentaPak should improve the user's posture. This, he says, is because the design causes the pack's shoulder straps to pull straight back on the wearer's shoulders instead of back and down, keeping their shoulders from rounding forward. The anatomically curved mesh is also claimed to provide support to the lower back and lumbar region.
Should you be interested, the VentaPak is currently the subject of a Kickstarter campaign. Assuming it reaches production, you can get one for a pledge of US$28 – that's about 30 percent off the planned retail price.
Sources: Kickstarter, VentaPak