Line 6 FBV4

Pretty basic, I bought this to gain access to pedal mode on my spider2 amp. Guess what, you can't!
No info prior to purchase thanks to their ****ty website and lack of any support.

The only bonus over the FBV2 is the tap tempo function. Oh, and direct preset access, once you're used to this it is hard if impossible to go back to the fbv2.

The plug is standard pc type, which is good. It tends to pop out far too easily, which is bad.

Overall it costs too much for its lack of functions (with a spider2 series amp it is), and I hear the FBVexpress is cheaper&a tad better so...

Try it before purchase, with your amp unless you'll have a nasty surprise as I did.
Americans are lucky to have performant stores with no-fuss return policies, but in many countries you're stuck with the item you bought.
This is my case, and I plainly hate line6's lack of correct info.
Lie by omission, at least!