This is a shell for the Monkee Mods Firefly, a shell-ejecting pump action shotgun blaster created by Colonel Wasp and distributed by Monkee Mods. It can be used for the original blaster, but can also be used in blasters that use this shell type. This model was uploaded to Printables to make this model easier for people to find.

Credit to JLfamala on Thingiverse for creating the original model.

https://www.thingiverse.com/thing:5982486