underground 512 hz receiver

underground 512 hz receiverMODEL NO.WPS512LSUPPORT CUSTOM-MADE, accessaries changeable.Product features:FM Locator: (transmitter&reciever)1 Transmitter: send 512HZ frequency.2 Reciever: receive the frequency and locate the bad pipe.SpecificationTransmitterReceiver1 Size: Φ22.5*L48mm1 Size:512*110*1182 Power source:#357 button cell noncharge2 Power source:6AA Alkaline3 Battery life:3-4hours3 Battery life:30-40hours4 Frequency:512Hz4 Frequency:512Hz5 Tone type:Beeping or