The best electric fillet knife
Use Mister Twister now... much better, but the lock areas that hold the blades are made of plastic and known to fail. You'll be cleaning a fish and it seems like you have a dull knife .... then if you put resistance against the blades individually you'll see one is vibrating, but not driving back and fourth.
I have on old bread knife that I found at a rummage sale. All metal parts, better motor, that thing will out work any other knife I have ever seen.