It's a non-bench mount reloading press that uses special dies and works sort of like squeezing the handles on a pair of pliers. Nifty lil gadget, but a bit pricey fer my blood. But it is authentic to the old west, they've been around fer a heck of a long time.
I prefer the Lee Hand Press myelf, same portablilty, less cost, and uses standard dies from about any company.