I recently purchsed a used F75SE2 (12-14-14). I have been running a 13" Ultimate Coil on it. It is a bit heavier than I'd like. I like the factory 11 inch Biaxial DD coil but I would like to hear from those who have used the SEF coils (the one that is a bit larger than the 11 inch factory coil). Is it lighter than the Ultimate when installed? As deep? Anyway, I found a couple of 69 cal roundballs with the Ultimate Coil (JE Process.....Sens set at 95.....zero disc) and one of the round balls was two inches deeper than my Garrett Pinpointer. By no means am I bragging on my abilities. Just giving a comparison as I might invest in an SEF butterfly coil. (the one that is larger than the stock 11 inch coil). Anyway, Happy Searching!!!!! kevin