One of the most useful tools I own. Milwaukee makes them for both 10 ounce and quart tubes.
Mine is a 12v-14.4V battery one that I bought in about 1999. It's still on the original 12V battery. It looks like it's been through a war, but it still works perfect.
No telling how many hundreds of tubes of caulk have been run through it. 12V is plenty of pushing power - it will split a tube open if it can't push the caulk out. I used it yesterday - it will empty 10 or more tubes of caulk easily on a charge. It reverses the motor at the end of each squirt to keep it from dribbling caulk everywhere.
Mine was originally set up for smaller caulk tubes, but I bough the adapter for the larger ones - it includes a new carrier and a longer ram that can handle the bigger tubes. I normally leave the smaller tube carrier on it, because my jobs aren't that big.
I've considered just buying a dedicated one for the bigger caulk tubes.
