I've created this silencer for my ASG CZ-P09 airsoft gun, so it still fits in the holster.
The end cap is just hold on by camo tape, but can be glued on if wanted.
I glued a bit of foam onto the infill parts, to create small pockets to catch the air and do the silencer stuff.
Assembly with a M3 x 20 bolt and M3 square nut, coming with the prusa printer spare parts.
Mount the silencer on the 14 CCW cap of the outer barrel, and then tighten the bolt.
Easy to print in PETG with no need of support.
The author hasn't provided the model origin yet.