I have a Silver U Max with the standard coil..I placed a WTB in the Detector classified for a 3 by 18 wide sweep coil.If I get one, that solves one hunting problem..The other is very trashy ground..Small coils are reputed to be less sensitive to masking than larger coils.. Everyone seems to favor the 5.75 inch coil for this kind of site...But, there is a 4 inch coil , also, sold by Tesoro....Would the smaller coil be better in a trash environment? Simple Spock logic never works..., What am I missing, in seeing the 5.75 is more popular than the 4 inch coil? As ever, many thanks for your input..Cordially Nad