Capsule is a reverse-stress, high-contrast, rounded sans-serif font with two distinct personalities. An all-caps face, there are however variations of some letters in the lowercase slots. The lowercase variants are more playful, with more bulbous elements that riff on phototype faces like Amelia and Data 70, but all can work together and be mixed and matched to your heart's content. Capsule boasts a bunch of esoteric discretionary ligatures to play around with, and stylistic alternates for 4, 7 and £. The language support is extensive enough to set essays in most Latin-based languages, even though that's the last thing you should be doing with this font!
Capsule should be set large. The fit is tight and the kerning is aggressive. It's not what you'd call a workhorse, but Capsule is an All-Caps you'll (see what I did there?!) want to use for impactful headlines, cutting edge logos and post-modern layouts.