The Ciseco RFu-328 BARE offers all the convenience of the Ciseco RFu-328 and allows you to add your own radio unit in place of the Ciseco SRF which is supplied with the standard RFu-328. It was created to support those people who want to use a Hope RFM-12B unit instead of the Ciseco SRF for instance. You will see the RFu appearing in other peoples products too like the Open Energy metering solutions http://openenergymonitor.org/emon/
Please note that if you want to add an SRF yourself, you need to chose the CC1110 based unit. If you want the Ciseco SRF on board, we recommend you buy the Ciseco RFu-328, saving you a lot of trouble soldering.
Please refer to the RFu-328 technical data for dimensions, but note that the electrical characteristics will depend on the radio unit you supply.