Thanks Multi, I have something like that on my Hobie(without the spring). What I need is a setup that would mount on a horizontal surface. Single small block(5/16 sheet) with a cleat coming off. It's for a small monohull(Cal21). I guess I need a base, and a spring, and a block that can sit in the base, and a cleat that will somehow attach. Suppose could do w/o the spring as the sheet comes down from the boom. The current rig is very unacceptable.