It's a tape that has strong adhesive and a felt-like backer that you would tape over a blister or chafed spot in a boot or shoe. The adhesive is sweat proof, and the felt backer both pads the sore area and also prevents further sliding and rubbing that leads to chafing and more blisters.
In a pinch, you can also use it to patch worn-through insoles.
Nah a lot of times government inventions get sold under license. Gov invents it and private industry perfects it. Within 5 years you'd have Darn Tough blisterproof socks and gov gets a fraction of every sale. It's how NASA has the best ROI in the government.
