How it's made. Two printed parts in PLA (or PETG), no supports and no hardware. The drawer prints flat: 2.4 mm floor, 50 pockets at the cartridge's largest diameter plus 0.6 mm so every round drops in and lifts out, standing 7 mm proud; a faceplate at its front with the text inlaid 1.2 mm; and on each side a 20 mm cantilever tab carrying a ramped button. The sleeve prints standing on its closed back, a 2 mm tube with a window in each side. Sliding the drawer in, the buttons' ramps press the tabs inward; at home they spring out through the windows and their square faces stop the drawer — pull force goes into the sleeve wall, not into a flexing part, which is why this holds where a snap lid doesn't. A lip on top and a recess underneath let the sleeves stack straight. Rifle boxes (.223, .308) are taller and longer; every size prints on a P1S.