The Tonecore models used a modular system where the pedal circuit in a little box (module) could pop out of the pedal enclosure (dock) so you could use different effects with the same footprint. It was kind of a half-baked idea and did not last long. You cannot use the module on its own. The idea was that you'd just buy one or two docks and switch out the modules to save money and space, but only a handful of the modules were any good and they weren't actually very cheap or convenient.

This is what you'd be missing, basically the footswitch, the enclosure, and the in/out jacks. Certainly not functional without those.