There are meant to be different versions of the HTS-14, one of which is with a suppressor. This Hephaestus Dummy Suppressor is made specifically for the Hephaestus HTS-14 and it's very unique.
It comes with a alternative flash hider which is user to attach this suppressor. The suppressor itself is CNC machined steel construction making it incredibly heavy, with a abrasion-resistant black finishing.
What's so unique about it is that you can split the suppressor in half by unscrewing the top from the bottom. Inside is space for a Marui-spec Tracer Units so long as it is:
14mm- (anti-clockwise thread)
Diameter (max) : 37mm
Length (max) : 200mm