Tried the RC40 over my test bed which is iron infested and loads of hot rocks . Its called the Pit field . Cant believe how well it worked . First test Wafer thin Lizzy1 hammered only 3/4 and a hole in at 8 inch . The racer 2 with the rc40 coil hit it in all modes at 90 gain GB was 60 . next the Vicky tanner at 9 inch 2 way also .Also blow my lugs off with the 2inch buckle at 14 inch . And actually hit the 12 inch Vicky penny which is a very difficult signal as must be iron close bye . next 12 cartwheel pennies at 14 inch SOLID and finally the one that hasn't been found by CTX 17, Noxie stock ,Deus13,Impact 13, euro ace stock a piece of 2 inch square lead half an inch thick at 17 inch AND THE RACER2/RC40 2 WAYED IT . Also iron near bye so a very difficult target . The theory says big coils are not good with small coins . This lizzy is WAFER THIN HOLE AND ONLY 3/4 IN SIZE . And the racer2 /RC40 Nailed it ?????????? So that's one theory gone tits up lol. I always use a harness so the size will not be an issue . I am on the bench at the moment twisted my knee so taking it easy for a few days . Cant wait to try The racer2/RC40 on a bit of nice pasture . Set up with it .