Like a lot of P2V new-er pilots, I worry about making a stupid mistake and inadvertently sending my quad copter off on a flight to parts unknown. So, after reading lots of comments here, I decided to buy a GPS tracker to install, and I ordered the first of what would turn out to be three of the "devices." The first was a very simple one that never worked, and so I turned to the TK 102, that several folks recommended. After dealing with two different Hong Kong-based "suppliers" for a TK 102 tracker, and getting two units that were junk (one worked for about 3 days, the second one never worked at all), and having both sellers be impossible to deal with, I decided to bite the bullet, and I ordered a Spot Trace http://www.amazon.com/SPOT-Trace-Th...F8&qid=1407773016&sr=8-1&keywords=spot+trace). Oh, and my ATT sim card ended up costing me more money. They guy in the store sold it to me at a rate of $5/month for 200 text messages. I paid him $15, for three months. As it turns out, though, the money for one month does not carry over to the next. I learned that when my balance was suddenly zero. And, to make ATT even more endearing, while the plan costs $5 per month, the lowest amount of money you can add to an account is $10. So, gosh, what an honest company -- The $5/month plan costs $10/month and nothing carries over. So, while the Spot Trace is a bit larger and heavier, and I'll loose a bit of flight time, this unit appears to be a real device, and I bought it from a real store (REI) where I can take it back if it doesn't work. I blew roughly $70 trying to go cheap with a tracker for my P2V, and now spent $99 on a real device, and will spend $99 for a year's tracking. This will give me much greater peace of mind when I fly. Am thinking about making paperweight out of the three junk Hong Kong units.