Dual Injection is a dual booster with two high quality clean boosts from Carl Martin. You can also switch between parallel mode and serial mode with a pin switch.
Parallel mode can be used as an overdrive booster and the other connects to the effect loop for volume boosting. The serial mode allows you to boost the distortion with 2 levels of boosting, so you can get more powerful and powerful to match your songs.
Dual Injection can be used in a variety of situations, depending on the idea of use.