In street applications that experience cold starts and high pressure surges the race designed non-bypass filter can be less than ideal. Although some engines have bypasses in the block, some do not. This cap would allow any street application that doesn't have a bypass in the block to add one to our filter. The cap uses the same hardware and O-ring from the original cap and works with the same Canton CM filter elements. Protects against cold starts and thick oil pressure surges by opening the bypass at 11 psi pressure differential.