A disk drive unit having a disk loading mechanism, for use in a mobile device. The insert carries a feed lip that fits through a loading port orifice in the feed tray to direct shorter ammunition downwardly as it is being advanced towards the weapon breach for loading. The main body of the meter movement is situated in an aperture in the circuit board. The logic block coupled to the several test structures selects a desirable test structure from the several test structures. 01-40% by weight in solids relative to the total amount of the ink composition.