The American Fibertek MR-0500SL is a low cost, low profile 20mA current loop data transceiver system. Data transmit and receive is accommodated on one single mode optical fiber. These products are compatible with the AMAG M2100 DBU and M2150 8DBC access control equipment. The 0500SLs are factory set to be passive inputs and active outputs. However, the units have internal jumpers to allow independent field setting of the inputs and outputs to either active or passive, if required. Transceivers are packaged in compact extrusions.