This is the most overpackaged part in our line, and we aren't proud of that. They're genuine Shimano brand "Inner Caps"--is what Shimano calls 'em, although we just know them as the aluminum cable end tip crimp thingies, to prevent the cable from fraying and scratching you and giving you tetanus. Pinch them on gently with side cutting pliers or pound them flat with a rock.
For 1.6mm brake cables.
Secret tip: scoop up some grease with the open end so that it sticks to the cable and doesn't fall off or get catapulted across the room before you get to pinch it on.