The VM-540 Sonde Locator comes standard with sonde/camera frequencies of 512Hz, 640Hz and 33kHz, making it compatible with the major push cameras and crawler cameras on the market. In addition to a visual peak bar graph that reaches its peak when over the sonde, a matching audible tone is heard which is loudest when over the sonde. The dot matrix display in the VM-540 shows a peak response in a bar graph with matching signal strength numbers, battery condition, speaker level, frequency setting and depth to the sonde with the push of a button.