This is the professional model with all the bells and whistles. This reader can run 4 x 3m or 4 x 6m mats. The distance between the reader and the mats can be up to 25m (and in fact more if an extra power supply is fitted). The reader can connect to your laptop by ethernet cable, WiFi, 3G direct to the web or by radio modem. This is the system used by the Pros on the big (and small) races to time the start/finish/splits. It is highly accurate and very portable. (the reader weighs only 7kg).
TM Club XR
Basically the same unit but without the built in 3 G capability and it can "only" run 2 x 3m or 2 x 6m mats. It can communicate by WiFi and also by Radio Modem. It is ideal for clubs and also used by Pros for split points in a race. The fact that it can communicate over large distances makes it ideal as a remote timing point.
TM Club Lte
This is ideal for the club on a strict budget. It can connect to the laptop by a simple ethernet cable and runs 2 x 3m or 6m mats. In fact it has most of the features of the Pro but runs only 2 mats and doesn't have the fancy comms.