Stant 10335 Lev-R-Vent Radiator Cap - 20 PSI
Stant LEV-R-VENT radiator caps fit in the smaller spaces of today's engines, while providing a pressure release lever and may fit on applications where older, larger-shell caps may not. A tab on the bottom of the lever interlocks with the filler neck to prevent removal of the cap until the lever is lifted.  When the lever is lifted, the entire pressure valve is lifted off the lower sealing seat in the filler neck, harmlessly venting pressure through the overflow tube