The UR-7KH is a COMMS module (communications module) for use in the Multilin universal relays. The UR-7KH is of the 7K variation of the type 7 communications modules. Not all variations can be found in a specific universal relay. It is important to consult with the order options offered for each of the Mutlilin universal relays to understand a comprehensive view of the variable options for that specific relay. For example, the UR-7KH might be found in the T60 transformer protection system. There are specific order code tables in chapter 2 of the T60 product catalog that show which type 7 communication modules can be included in the relay system. The 7K order code indicates a two-channel single-mode module with a 1300 nm LASER wavelength. The 7K COMMS modules are configured in the same way as the 73 module, 72 module, and 7D fiber-laser module, with two channels. The first channel is oriented over the second channel in a vertical orientation. The first channel has a Tx1 and an Rx1 section and the second channel has a Tx2 and an Rx2 option within the laser fiber module.