The M45E is a pump-action, magazine-fed, dual tubular, 8-gauge shotgun that was designed as a variant of the M45 Tactical Shotgun. Its design heavily influenced that of the M90 variants, which were designed as more economical replacements. The M45E was in use by the UNSC Marine Corps until at least September, 2552.
The design of the M45E is extremely similar to that of the M90 CAWS Mk. I. Weapon System Technologies took Misriah Armory's M45E design and streamlined it, making it more efficient and easier to mass-produce. As such, it uses Soellkraft 8 Gauge Shells with a 12 shell magazine.
- Halo: Combat Evolved Anniversary (First appearance)
- Halo: Combat Evolved Anniversary, Kinect Library, Shotgun, "Weapon System Technology recreated a more economical and practical version of the M45E in their M90 Close Assault Weapon System"