Double ram design so you can keep two dies set up all the time.  Herters marketed these in the 60s and discontinued them in the early 80s I believe.  Like all Herters reloading equipment, it's built hell for stout, weighs about 35 lbs.  It uses any standard  7/8x14 dies from any manufacturer, however, it does use the old style Herters shell holders which you can find easily on Ebay, or you can just get an adapter to use modern shell holders, both RCBS and CH4D sell them.  The good news is, this one already has two installed, they are for the standard .30-06 head size so will work with many cartridges that share that head size (.30-06, .270, .308, .243, 6.5 Creedmoor, .45 ACP to name a few) so very likely already set up for something you want to reload for.  These aren't real common and this is a nice one.  I am trying to pare down my collection of vintage reloading stuff, so I'd like to see this go to someone who will appreciate it.  Seven-eight-five-three-zero-seven-zero-two-one-seven.