Save when you purchase a 4 pack. The RC66RX has more codes available than it's predecessors (RC65RX, RC65R and RC64R). It can do everything the Infrared(IR) can do, and more. It's Radio Frequency (RF) capable, so you don't have to point your remote at your receiver to control it. You change channels from other rooms. Older model receivers may require an antenna to use this remote in RF mode (look for remote antenna input on the back panel of the receiver). This remote will also work in IR mode if your receiver is not RF capable (must change remote to IR mode).