I think you're thinking about one of the quick reaction red dot-type sights.  The one that appears to fit the bill is the Docter red dot sight and mount.  (Burris also makes a similar sight and mount.)

 

From what I can tell, the mount replaces your rear sight on the Glock and the sight attaches to it.  The front sight can stay put.  As long as you don't have a holster that completely encloses the pistol or a holster flap, you souldn't need a special rig for this set up.  Check out the various red dot sights at www.opticsplanet.net.  They have some very nice rigs for pistols and rifles. 

 

Another good accessory for the Glock is the Crimson Trace Lasergrip sight.  (I have several: one on a Series 70 Combat Commander .45 auto, one on a Beretta Model 92FS, and one on a S&W .38 Special snubbie (6-shot).  The laser is a great intimidator.)

 

 

but does the laser show the pt of origin

 

to the bad guy???????????

 

da riverChief

Chief,

 

The laser cannot be seen from the side, but it can be seen from the front (or bad guy's side).  Of course, you just see the red dot.

 

Just about everyone on the planet knows what the red dot means -- it's a laser sight and there's a firearm of some kind attached to it -- and it's looking for a target.  The intimidation factor is a very strong component of the laser, because the bad guys know if they're painted they're going to get hit.  There's not any doubt about it.

 

In a lot of tactical situations, many cops have had bad guys simply give up when they were painted by the red dot (or dots) because they knew that the likelihood of the guns with the lasers missing the shot were zero.

 

All this being said, the laser does have it's limitations.  (1) The dot washes out in bright sunlight and is best used in dark or low light conditions; (2) the laser light (and targeting dot) is affected by water droplets suspended in the air (fog) and by smoke particles that break-up the beam; (3) the laser follows a line of sight and the projectile follows a trajectory: this means that the laser and firearm are sighted-in at a given distance and there will be some dispersion caused by increases or decreases in range; and (4) targeting becomes ineffective past 100-150 yards because the dot gets too big.  However, within its limits, the laser is a tremendous asset for rapid shot placement on target in a very short time.

 

The Lasergrip sight for the Glock is a very effective and efficient quick engagement tool.  The lithium batteries (2) seem to last forever and, on most of the Lasergrip models, you can turn the unit completely OFF when you don't want to use it (such as in bright daylight).

 

MG