The Ashtech ProMark 2 GPS (L1) is a reliable and accurate surveying equipment designed by the reputable brand Ashtech. This GPS model has been tested and is in good condition, ensuring that it provides precise measurements for various surveying tasks. With its L1 frequency, this GPS device offers reliable performance in different environments, making it a valuable tool for professionals in the field of levels and surveying equipment. I acquired this unit from old surveyor who closed shop. Nice little L1 receiver, runs on (2) AA batteries and includes cable, antenna, bag and other accessories.