From WIKIpedia:
"The ASP is a custom made handgun designed and built by Paris Theodore (owner of Seventrees, Ltd., a custom gun leather shop in New York City) from the early 1970s to 1987. The ASP was based on the Smith & Wesson Model 39 pistol. The ASP featured clear Lexan grips allowing the shooter to see how much ammunition is left, a rounded hammer, hooked trigger guard and no front sight. The ASP was responsible for later innovations made in the development of concealable handguns."
There's more on the website, but that's the gist....
One on auction sold for $4k....