K&N KN-171C Harley Davidson/Buell High Performance Oil Filter O/E replacement oil filters for most cars, trucks, SUV's, motorcycles, & ATV's 17 mm exposed nut designed for easy oil filter removal Heavy duty construction for extreme conditions Resin-impregnated filter media traps 99% of harmful contaminants Anti-drainback valve (where applicable) eliminates dry starts, prevents oil from draining back into crankcase during engine shutdown