I own 2 different models of Crimson Trace LaserGrips for my Glocks. Those include the wrap around style LG-400 series and the earlier backstrap style LG-600 series. The LG-400 series has a lower-profile diode module that interferes with slide operation less but I prefer how the LG-6XX series makes the Glock’s grip feel (they straighten the backstrap a bit, reducing the grip angle). I have often wished that I could combine the best of both styles and it appears that Crimson Trace has done exactly that with the introduction of the LG-637 and LG-639 with both red and green lasers.
The LG-637 and LG-639 fit the Gen3 Glock 17 (and similar) and Gen3 Glock 19 (and similar) respectively. They attach to your Glock’s backstrap via a provided, extra long locking block pin. The laser module appears to be smaller than that of the original LG-600 series LaserGrips and it is available with either a red or more daylight visible green laser. Additionally, the LG-637 and LG-639 feature a push-button master on/off switch like the LG-400 series LaserGrips.
These look like the best Glock LaserGrips yet! Check them out at Crimson Trace.