If you buy one off eBay, make sure it includes the USB transmitter/receiver. Most if the Tranzports I've seen sold there don't include it making it worthless if you don't already have one. I know this because I bought one of them. So maybe y'all can learn from my hard experience. Lol. The second one I bought specifically said that it included the transmitter and thankfully that seller was not as deceptive as the first.
Regards,
Don