Pingers are devices that generate acoustic signals underwater. They are used to mark an underwater site or piece of equipment so a returning diver, using a pinger receiver, can locate the exact spot. Pingers are available with different transmit frequencies so several can be deployed in the same general area without interference from each other. The diver adjusts his pinger receiver to the frequency of the desired pinger and the receiver leads him directly to it. 

JW Fishers family of commercial grade pingers include both the Single Frequency Pinger (SFP1) and the Multifrequency Pinger (MFP1). The SFP1 is available in several frequencies one of which is specified at time of order (22, 32, 40, or 50kHz). The MFP1 has user selectable frequencies from 20 to 50 kHz in 500 Hz increments. The operator selects one of 60 different frequencies before deploying the pinger. Many pingers can be deployed in the same general area, each broadcasting at a different frequency. This enables a diver with a pinger receiver to pinpoint the exact location of each pinger without interference from the other pingers.

 
Fishers pingers are very flexible allowing the operator to select the number of pulses per second, the length of each pulse, and the output power. The length of each pulse and output power adjustments allow the operator to adjust the distance the pingers can be detected. With the MFP1 the transmission frequency can be selected by the operator before deployment. These features make the SFP1 and the MFP1 extremely versatile and the first choice for almost any application. 

Power for the pingers is supplied by two standard alkaline 9 volt batteries which last from a few days to many months, depending on output power and pulse selection. For long durations lithium batteries can be used. A longer housing is also available which holds six batteries to give 3 times the normal operating time. The pinger can be automatically activated when put in the water or manually activated with a switch. 

All Fishers pingers are covered by a full TWO YEAR WARRANTY.?br>