Gel Blasters use airsoft technology and now Nerf? Dr. Flux got a QWK Challenger MK3 Foam Dart Blaster AEG to show what it does. The Challenger is available in two configurations: the Standard Edition and the PRO Edition. Both versions have an ABS exterior, a MOSFET, a blowback action, and metal gears in the gearbox. The Challenger is not just an AEG blaster, it also has a MOSFET that lets you choose your firing mode: semi-auto, 3-shot burst, or full auto.