The Loop is based on the H&K MP7 with an extended barrel. Although the MP7 is actually a personal defense weapon in real life, it is classified as a rifle in-game due to lack of the proper weapon classification in the game.
It has a dark metal receiver with black plastic pads on the sides of the user half of the receiver and two unused picatinny rails on the sides of the other half. The standard iron sights are folded down out of the way of a reflex sight sitting on top of the weapon. The weapon also has a retracting stock and folding foregrip, which are quickly taken into the battle mode during equip animation.