The DFS Booster are loaded into your DFS HUD/Profile. There are many different types of boosters, and they will speed up the working time of that specific product.
How to use? Rezz it out and click on it, then it will load the information into your profile and will automatically be used when you use that equipment type, similar to the freezer. It will lower the work time to a minimum of 60 seconds per craft. It will still be used up even if the item only takes 60 seconds to make. There is no way to turn it on/off at choice, once it’s loaded it is ready to use.