Yes it is two LNB's in a single housing, set for a four-degree-satellite-spacing. It has the ability to switch from one side of the LNB to the other based on a tone sent from the receiver.
There are two models of LNB that match the model of the dish: the 60e LNB must be used with the 60E dish; the 75e LNB must be used with the 75e dish. They are not interchangeable
You need one cable for each tuner. If you have a PVR (DRS530 or DSR630) containing 2 tuners, 2 coax cables are required for that receiver. Otherwise, a single cable is required per receiver. Each of the four outputs on the LNB is identical.