The DCPA-4k Plus is a complete kit that comes with one DCPT-4000 wireless probe transmitter and one RE-4k Plus receiver. The DCPT-4000 transmitter operates on three CR-123A batteries (included) and has 50 feet of direct burial wire connecting the probe to the exterior case. The probe detects vehicles passing by within approximately 10-12 feet. The RE-4k Plus receiver has 2 Form C relay outputs and one 12 VDC output. The relays and 12 VDC outputs can be set for 1, 5, 15 seconds or 5 minutes. The relay outputs can be used to connect to an alarm or home automation control panel (not included). The 12 VDC can be used to power a bell, siren, strobe or other 12 volt device. The distance between transmitter and receiver can be up to one mile.