I have had a Trutrak for 3 yrs. You buy a tracker from them and just add as many month's top-ups as you require. I usually buy 3 or 6 months at a time and skip a couple of months in winter. The tracker that I have is only 2g and has worked fine in France, UK and Ireland although their shop now features 4g units. I have found customer service very good; they also serve the fleet market. There were some special offers a few weeks ago which may still be there.