Check out this link, this is what I'm talking about. You simply unscrew these things and then place them on the trigger guard and tighten them down with the allen wrench that is included in the package.
http://cgi.ebay.com/NEW-LaserLyte-U...in_0?hash=item2c50e0ef18&_trksid=p3286.c0.m14
http://cgi.ebay.com/NEW-LaserLyte-U...in_0?hash=item2c50e0ef18&_trksid=p3286.c0.m14