A simple buffer, very small and very green. This can only be analogical, placing the end of a chain of effects pedals, before the return of the loop. This is an essential accessory if all pedals have "true bypass".
It publishes no sound as it is devoid of any order, there is nothing more simple. Not bulky on the pedal.
He does what he must. Totally transparent, it avoids loss of signal at the end of effects chain. Especially preferred that there are many patch cables.
I use it for two years and will buy a 2nd I will put before the chain front because I changed my tuner. The former was buffered and the new is not. What I like best: it is built by a famous brand, no more expensive than other comparable (Visual Sound, for example) and very small. No defect, perfect 10/10.