Looking for a noise gate to record with and jam with

There's two pedals, one has a G the other doesn't . What's the difference?
The normal Decimator pedal has only one input and one output. It's commonly placed between the guitar and the amp.

The Decimator G-String has two In and Outputs. One path to place it between guitar and amp, and then you can also connect it to the FX loop of your amp.
It eliminates the (constant) preamp noise and makes it possible to use the same threshold setting for both clean and distorted sounds.