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 signal. Rockwell Collins also manufactures a GPS receiver known as the "Polaris Guide", that looks like a DAGR, but uses only the civilian C/A code signals. These units are labelled as "SPS", for "Standard Positioning Service", and may be possessed by non-military users.