What will fit inside? Each TAC-PAC comes supplied with 2 inserts (1 die cut and 1 blank), a storage pouch, and the hard case and rubber lid. It is a complete storage system. The LE insert holds (8) CR-123 batteries. The MIL insert holds (4) CR-123, either (2) N or (2) AA, and (1) 1/3 N size batteries.  Battery Storage The inside housing is about 3.3� wide X 3.5� high (including the housing radius) and .85� deep and will accept parts that fall into that size range. It will easily hold an AR-15 bolt and firing pin. When assembled, it is just slightly thicker than a pack of regular cigarettes. The blank inserts can be hand cut. The black pouch version comes with an LE insert and one blank.