Red Laser sight - brand unknown. Mounts on standard rail. I have it for about two years - honestly can't remember where I got it from and there are no markings on it. It has sat on my desk glock at home and has seen limited range use just to zero it. Probably no more than 50 rounds if that shot with it on. I have since upgraded to a laser/light combo.
Solid aluminum with push-button quick release. Works perfectly - in very good condition.
See pics at http://www.lavasys.com/laser/
$40 includes shipping to lower 48. I take pal pay or money orders.