AR3 - Firestik Adapter SO239 To BNCAllows the user to utilize a PL-259 terminated coaxial cable for connection to a scanner or handheld radio that has a BNC antenna termination. Just screw it on to the coax cables PL-259 connector and connect it to your BNC terminated device with a simple push-n-twist motion. Adapter, so239 to bnc MODEL NO - AR-3