This is an adapter to connect a DeWalt 20V Max battery to a Ridgid 3 Gallon Shop-Vac. Ridgid and DeWalt battery packs have the same voltage even though they are branded differently. Installation is a bit involved as seen in the assembly instructions. As far as I can tell, the vacuum does not prevent the battery from excessively discharging. It is possible the battery will be damaged if you run it completely dead. Please leave a comment and let me know if you have any questions.