In February of 2017 I messaged back and forth with Sarah Wong from Shenzhen Carscop Electronics Co., Ltd. about gps tracking needs. I told her where I am located and what my tracking needs are. She told me about their trackers and platforms. I asked if there were any hidden charges or fees. She said that there was none. Upon paying for and receiving 3 trackers, Sarah then notified me about having to buy SIM cards (charges and fees) to work the trackers. She made it sound like I should know that and it was common sense. I called her out on misleading me, but went ahead and bought SIM cards for the trackers. Well, the trackers only work on 2G and take a unlocked SIM card and so forth. After spending another $80 on a few different SIM cards, I find out that these trackers don't work in the USA, if they work at all! I messaged Sarah about this. She responded that I can return them to China and she would send me back the 3G correct ones. So now I have to eat the cost of shipping them back as well and take the chance that they actually sell a product that works. All of this after spending additional money on SIM cards that Sarah mislead me on. Based on Sarah's responses and lack of accountability, I would say that they don't sell a product that actually works. Buyer Beware - There has to be better companies to buy from because carscop is not legit!