Amtech license that technology. At the time of the AAR's 1991 mandate, six vendors sold AEI site equipment. Those vendors were US&S, Safetran, Harmon, VideoMasters, CCTC International in partnership with IBM, and Southern Technologies. As of August 2007, only two of these vendors remain, SAIC (formerly VideoMasters) and Southern Technologies. Usage As of 31 December 1994, Amtech had shipped over 3.1 million tags to railways in North America. The AAR reported that over 95% of the North American rail car fleet was tagged. Over 3,000 readers have been installed by the railways in North America as of the end of 2000. Amtech was bought by TransCore. TransCore is today the most important producer of RFID tags for rail in the world. The AAR's S-918 specifications outline ten recommended frequencies ranging from 902.250 to 921.500 MHz, depending on the location of the reading device (in a yard or trackside), with a nominal transmitting power of 2.0 Watts (measured at the transmitter). References External links ACI A description of the earlier ACI barcode system Intertech Rail Transcore Epix Rail technologies Automatic identification and data capture