These intake adapters allow you to run a S2000 intake manifold on a K series head. There are two different versions depending on which head casting you are using.
Version 1 fits K20a2, K20z1, and K24a1 castings
Version 2 fits K20z3, K24a2, and overseas K24a3 castings. The water port thread is 3/8 NPT
Some modifications to the manifold are required