OCT600-UD is a tracking device special for fleet company. It is helpful in long distance transportation. Data logging feature can store the data when the car is in the area without GSM network, and upload the server while network is recover. Server will give you a confirmation after all data transfer complete, to ensure no lost of data. And the key to offer a big help in fleet management is data download feature.You just need to go to the car, connect it with universal USB disk, and start downloading, the whole process just take a few sec. No need to remove tracker from the car.All data correction can be done in a short, and minimize the amount of time, reduce a lot of paper work.