GMRS Radios come in 2 basic flavors. Standard GMRS FRS radios pictured below on the left such as those type purchased at Walmart etc.. They are low power and will not work with a repeater. Range is limited. Their advertisement claims many miles range. Unfortunately not true.
They are considered simplex type radios. They transmit and receive on the same channels.

  The GMRS pictured on the right will support operating with a repeater. They are considered duplex capable radios. They can also be operated simplex and capable of communicating with the radios on the left. They are $48 for the pair. They can be purchased on Amazon. Click the image for the Amazon link. There are of course other duplex type GMRS radios available.
There are also mobile radio and antenna systems the can be installed in vehicles and as base stations increasing communications range.
We urge you to do some research for happy communications ahead!

  Simplex Duplex defined.
Simplex uses the same frequency or channel (transmit / receive) to communicate between radios.

  Duplex radios can transmit on one frequency and receive on a different frequency. Thus allowing repeater operation. To be more clear to reach our repeater you would transmit on 427.600 mhz to the repeater. The repeater would then re-transmit your signal on 462.600 mhz the receive channel.

You must have a valid GMRS license to operate thru GMRS repeaters.
See our license page for info on getting your GMRS license