ADAPTER inserts into the front sight housing of the G3 rifle and variants. You can then press the G3 bayonet onto it , turn , and lock it in position. Specifically for lugs in the 9 O’clock position, but can be used with others if you drill a new locking hole in the position you require.
I bought this to allow mounting a G3 bayonet to a C308 / Cetme equipped with an upper rail forward of the siight tower. It works. The fit and finish are excellent, and I anticipate many years of happy skewering ahead.