Aloha from Hawaii: I have a Kohler bathroom sink faucet and the male connector on one fitting is 5/16" and the male connector on the other is standard 1/2" pipe. They are joined by a flex hose with a compression fitting at the 5/16" end. The problem is that all the hoses I can find with the standard 1/2" pipe at one end are either 3/8" or a few are 1/4". I can't find the proper hose anywhere and I can't find an adapter to convert the 5/16" male fitting to a more standard 3/8". Any suggestions? Many thanks.