Building on the innovative features introduced with the Armada Technologies PRO800, the PRO800D adds the flexibility of using 8 D cell batteries for transmitter power. In addition, we have kept the unique features offered by the original PRO800, including wireless inductive connection to cables, 20% more power, excellent wand noise rejection, and null/peak reception modes. With added power and AC noise rejection, the standard locate becomes the clear, powerful locate. Wireless connection means inducing tracing signal all through the ground, allowing the user to trace any conductor in the ground within 25-30 feet of the transmitter. Once the cable picks up the signal, track it for up to hundreds of feet. When it dies, relocate your transmitter to the lost spot and start again. Voila, infinite distance capability!