Focus ST Oil Catch Can kit Stage 1The Damond Motorsports Oil Catch Can kits come with everything needed for an optimized Oil Catch Can system. An oil catch can is, in a sense, a filter for the positive crankcase ventilation system. The oil catch can(OCC for short) is used to tap and contain blow by oils and condensed crankcase gases, that would otherwise flow throughout the PCV system back into the intake tract, and allows for draining of these fluids remotely. With the addition of an