It's a cheap M-ETAL one from Skirmshop
https://www.skirmshop.co.uk/100x32mm-dummy-sound-suppressor.html
I opened it up, removed the spring from the middle, cut the 2 foam inner parts (as per an old KM mk23 suppressor video) and then used them to sandwich a scouring pad strip I stuffed in to make an "O" (FoamScourerFoam). Will find out how good it works when the primary turns up, I want to get the pressure down low for a quiet (obviously not mk23 quiet) but fast follow up setup as I'd like to use this at the local skirmish outdoor site, they have a village, netting maze, castle, outdoor speedball field I think it would do really well at.