I can't be certain without more info but would assume it is a standard alloy frame. What you have there is an early non-rail P226 with a stainless steel slide. A friendly reminder that if you want good info you need to provide good info. Your picture isn't posting properly but I was able to use your (non-hyperlinked) URL to see the pic.
What year? 1998 or so? Early UU? I'll have to ask him to try the magnet if he can. Right side has no markings on frame or slide other than the UU603XXX serial to indicate USA made frame.
