Nerf Desolator

The Desolator is a clip system flywheel-powered blaster with semi-automatic function. It has two tactical rails above the blaster and two sling points: one in the handle and another one under the muzzle. It also has clear plastic parts, allowing the user to see some of the blaster's internal workings.

Despite being compatible with other clip system clips (such as a Buzz Bee eight dart clip), the acceleration trigger won't work when the clip is normally inserted. This is due to how loaded ammunition lines up with the blaster's acceleration trigger safety lock; pushing the clip firmly in place will help avoid this issue.

Source: http://nerf.wikia.com/wiki/Desolator