good, but no adapter connector
The Boss FS-6 is very usable with the boss looper RC-3. But probably it would be better to get the boss looper with 2 pedals RC-30.
This solutions is just as big and expensive.
I don't like that it only works with a battery and you have to remove the cable to turn off the pedal. This means that you can not turn off the electricity for everything at once but you need to remove this as well.