This Star Wars papercraft is an E-5 Blaster Rifle, the standard-issue armament of the OOM and B1 Battle Droids and the elite BX-series droid commando, the paper model was created by Black Fold Work Shop. The E-5 blaster rifle was a powerful, light, but somewhat inaccurate weapon.
The E-5 blaster rifle was manufactured by Baktoid Armor Workshop on order from the Trade Federation for their Droid Army.
The weapon had a large gas chamber that allowed for powerful blasts. It was originally a BlasTech design that was reverse-engineered by Baktoid Armor Workshop for use by its droid troopers. The fact that the weapon was intended for use by non-living wielders allowed BAW to skimp on some of the finer points -such as the fact that short barreled weapons are comparatively fragile and produce great deal of heat over repeated firings. While these factors might inconvenience a human soldier, a Baktoid Battle Droid has no complaints.
During the Clone Wars, E-5 blaster rifles were still used by B1 battle droids, but they were rivaled by the B2 super battle droids, which had a wrist-mounted blaster instead of a rifle, something that proved to be a more effective and versatile weapon. [Source: wikia]
You can download the paper model template here: Star Wars - E-5 Blaster Rifle Free Paper Model Download