the given length is for the internal thread alone (which is extremelly long for a thread, makes no sense). I contacted the seller before buying to ensure what length it was and they dont even understand english. they answer to my question was "OK". I bought the item expecting the description was adequate, but is not. now i have an adapter 30% longer than I needed. it is specially frustrating because I asked the seller this exact thing and was unable to even answer.
very good