The VATTENPDC GPS ATTENUATOR is designed specifically for the GPS L1, L2 and GLONASS carrier frequencies. The VATTENPDC is an active GPS Attenuator which lowers the RF level of the GPS signal by a 25dB range which is selected by the customer via a potentiometer knob on the unit. The signal can be attenuated over a 0 to 25 dB range. The unit will draw current from the center conductor to power itself and then pass the DC on to the intended GPS antenna or source.