AN/PSN-13 Defense Advanced GPS Receiver
The AN/PSN-13 Defense Advanced GPS Receiver (DAGR; colloquially, "dagger") is a handheld GPS receiver used by the United States Department of Defense and select foreign military services. It is a military-grade, dual-frequency receiver, and has the security hardware necessary to decode the encrypted P(Y) code GPS signals.
Source: Wikipedia — AN/PSN-13 Defense Advanced GPS Receiver (CC BY-SA 4.0)