This fits my Sumatra 2500 .22 perfectly and works. For those saying their moderator is in the way of things like the fill port, or air tube, this is not a problem with the adapter, but with the type of moderator. By design the Sam Yang/Seneca/Eun Jin rifles require moderators with sloping shoulders to clear the other rifle parts due to the barrel and air tubes being placed closely together. A flat base type moderator will not work unless it is very thin, and a thin moderator on these guns will not work anyway with the amount of power they produce.
This is an example of a moderator with sloping shoulders: https://www.urbanfieldsportsman.com/wp-content/uploads/2012/12/urbanfieldsportsman-398.jpg