AST Pressure Cap 13 / 16 PSI for Mazda RX-7 FD 1992-2002, RX-8 2003-2012

This is the pressure cap that fits both our original design RX-7 aluminum Air Separator Tank and the RX-8 aluminum expansion tank replacement / AST, with 2" neck..   

Our latest designs for both RX7 & RX8 use the smaller cap with 1" neck.