Cardora begins where your wallet ends: a single sheet of brushed stainless steel, cut to 0.8 mm and weighted at 18 grams, with nothing printed on its face. The chip signs every payment with a one-time code, the antenna answers a terminal in a third of a second, and the edge only catches the light when you tilt it. Tap it, save it, forget it — it works the same in Lisbon as it does at home.