The black Saturnworks reamp box converts a balanced line-level signal from a device such as a mixer or interface to an unbalanced instrument-level signal so that it can be put through a guitar amp. 

This allows you to record a clean signal, and send it back (reamp) it through a guitar amp/pedals to tweak it/add the effects.

The reamping box gives the signal the same characteristics as your original guitar signal so that you can do whatever you'd like with it, and you don't have to be playing. Pretty cool.

The premium 'black' version upgrades the pedal with a black powder coated enclosure, a Switchcraft USA output jack, and a metal knob on the output volume control. 

Reverb.com has a good article on the basics of re-amping here:

https://reverb.com/news/how-to-reamp-your-guitar-signal-in-your-recording-rig

and more info here:

https://reverb.com/news/how-to-use-effect-pedals-as-rack-gear

The Saturnworks reamp features:

• A passive design that doesn't require external power to operate.
• High quality Neutrik and Swithcraft 1/4” jacks.
• An Edcor USA transformer. These pro-grade audio transformers are made-to-order by a small shop in New Mexico. Over the years, the cost of these transformers has more than doubled. However, we've opted to stick with them, both because of their top quality and because they're made here in the USA.
• A solid 2.4" x 4.4" (1590B size) black powder coated cast aluminum enclosure. 
• A ground-lift toggle on the input to help reduce noise.
• A volume control on the output.
• High quality wire made in the USA.   
• A 1-year limited warranty against parts and manufacturing defects. See saturnworkspedals.com for warranty terms and conditions.
  

Check out saturnworkspedals.com for the full Saturnworks lineup.