"Besides the ammunition it fires, the P90 has a number of very unusual and unique features that make it stand out in the field of firearms. The bullpup layout of the weapon makes the P90 the most compact fixed-stock submachine gun made... The physical layout of the P90 is very unusual the first time an operator sees it. The grips underneath the weapon are oddly curved with elongated holes above them to allow the fingers to wrap over the grip. Once the weapon is picked up, the style of holding the weapon dictated by the layout of the grips becomes automatic."