(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.