It does exactly what it is supposed to do, great for reducing the power of tube amp for playing at low volume at home or for demo recording by using jack lineout or XLR DI out when used as dummy load. Metal box is solid, connectors and pots seems to be OK, easy to connect and use.
Big minus is altering of the sound from amp speaker. The sound from your speaker becomes somehow "dull" and muddy, lacking highs and mids comparing to straight sound without atteunator in circuit. As I said it is really great for practicing and demo recording , but unsuitable for live performance or recording sessions in studio.