Took my TDI Pro relic hunting to my old hunting grounds and WOW !!! Heretofore I have only hunted these grounds with VLF's and the difference between PI and VLF is startiling----in an area that has been low crawled for 40 years I was able to recover a pocketful of fired 58's in about 2 hours. Pulse Delay 10, GB 12, and in Hi I was able to cut the iron trash greatly. Gain was 8-10. I plan to go to an area where I dug many beautiful 4.2 Hotchkiss shells about 30 years ago and test the Pro there.