Vac: Pilots, Engines, Guns, Tanks, Wheels etc.
Armaments are weapons and supplies of war with which a military unit is equipped.
Most modelers will find these not difficult to detail and rather easy to assemble and paint.
Finding the proper sized parts for your model:
Photos are your best source for deciding what size weapon fits your model. A side or bottom view for instance is best for bombs. Measure the length of the bomb in the photo and compare it to key positions on the rest of the plane like the front of the cowl to the leading edge of the wing or perhaps the length of the canopy might be equal to the bomb length.
Measure the length between the same key positions on your model to find the bomb size you can use.