This is a generic silencer for the Airsoft rifle. The thread is LEFT handed M14 ( standard thread on the real and most airsoft rifles. Let me know if you require other sizes.

P.S. Regarding printing. I was in rush and needed something to cover my longer inner barrel on the G3SG1 rifle, so I printed this very quickly. So I printed this in PLA with resolution of 0.3mm per layer. As a result - layers are quite visible, so I painted it with a rubber paint. Do not like the final result and will reprint it with a better resolution.