Raceworks Round Catch Can AN-12 External Breather 1L – BlackDescription Raceworks Round Catch Can AN 12 External Breather 1L Black. An oil catch can or breather tank is an essential step in removing PCV oil before it enters the combustion chamber, and must be baffled while providing unrestricted flow to maintain efficiency and prevent intake carbon build up. Raceworks Catch Cans have been engineered to perform under the most extreme street and track conditions, featuring robot welded 5052 aluminium