The OXO Brew Rapid Brewer is a manual pump brewer for coffee concentrate. It uses a built-in stainless-steel filter and needs no electricity or disposable paper filters. Hot water steeps with the grounds, then the pump pushes the coffee into the serving vessel. It does not regulate flow automatically like a batch coffee maker.
A manufacturer's hot starting point is 20 g of finely ground coffee and 160 ml of hot water. Tamp the grounds, fill the water chamber, steep for 2 minutes, then pump. Dilute the concentrate in the cup to taste. The water added for dilution is separate from the chamber charge; a full mug's water must not all be poured into the brewer at once.
Shorter, more concentrated expert recipes are variations on these mechanics, rather than the default way to start.