Good question. I keep base units of popular models at my apartment (mainly vacuums) to test the batteries, power hoses, wands and power nozzles. There are a lot of repeats. Otherwise, I'll take the entire thing home if I can carry it to test what's practical to sell/ship, and part out/put the rest back outside. Otherwise, I'll take the loose parts I need to test and hold on to them until I find the rest what I need outside (again, since there are so many repeats).