What Bruce is referring to is the "conversion" which consists of both the pump and the base...you can re-use your bowl--ANY bowl that has the standard 4-bolt mounting pattern). Here's a link: http://shop.sailboatowners.com/detail.htm?group=1357&cat=1002

You CAN buy just the pump without a base...but I dunno whether the holes line up on a Headmate base either. Vic Willman, who was my Raritan "guru," would know, but he finally retired last fall after 40 years...no one who's there now knows squat that they can't look up in the current owners manuals. I'll try to find out...stand by for a day or two.