It works with both sources simultaneously so there is no either/or when choosing how you wish to operate the unit

Makes attaching bikes to trailers infinitely easier and safer than ever before

Noise reduction - 23dB SNR

Color is black anodized

Fast gravel roads on a weekend or piloting around narrow trails to find that perfect stopover for the night – now you can do it with complete control over your bike

K&N - Steel Base Crankcase Vent One Piece (62-1010) Options:62-1010 It works with both sources(Design For Competition and Off road use) 1. (2 diameter x 1 1 2 high), 2. (2 diameter x 1 1 2 high), 3. (3 diameter x 2 high). Steel base crankcase vent filters have vent tubes sledged into base. One piece design with rubber or chrome top. Filters with mounting studs can be mounted remotely but require vent hose and clamps. Filters mounted direct can be pressed into rubber grommets in valve cover.