Yes it is, actually the tx version is 3.17 and the rx is the diversity long range one 4.02 LR Long Range Diversity, (The current version of february 2010),
the same as the newer ones.
When i bought them the PRO version was the latest version as it was produced after the normal versions.
In any case the whole system can be upgraded.
https://www.webx.dk/rc/uhf-link3/uhf-link3.htm