I did my research on a lost coin..Will only be one trip there..Gold, silver dollar size, in very tall grass, may even try a brush hog.. I have a Vaquero, may take another for a back up. The coils I am thinking about.... 8inch concentric, standard 8x9 , a 10 by 12..The coin should be less than 4 inches deep, but the grass???? Does anyone have these coils, 8 inch concentric,10 by 12, that can run a Silver Dollar air distance maxed on their Vaquero...Don't know if power balancing will work when you are off the ground? Miserable excuse for a coin shop does not have a twenty dollar gold to air test...Thanks.