Designed specifically for GLOCK 17 Gen4 pistols, the LMS-G4-17 replaces GLOCK"s factory spring guide assembly with an upgrade that incorporates a high intensity Native Green laser beam for advanced target acquisition. Easily user installed without the need for gunsmithing or special tools, the LaserMax sight is housed completely within the firearm, making it as rugged as the gun itself. Produced exclusively by LaserMax, the patented Guide Rod Laser has been field tested through over 20 years of combat experience by SWAT, Special Forces, federal agencies and other armed professionals. Heralded for its cutting-edge design ingenuity by the Discovery Channel, the LaserMax Guide Rod Laser utilizes a pistol"s frame to protect the miniaturized electronics, placing the emission point of the laser beam in the dust cover area, in line with the bore for maximum accuracy. LaserMax"s signature Controlled Activation switch enables both left and right-handed shooters to activate the laser when needed, avoiding an inadvertent and potentially risky reveal of the user"s position. The location of laser and activation place the trigger finger in a position that reinforces NRA rules for safe handling of firearms. The LaserMax Guide Rod Laser does not restrict holster choice or interfere with the popular design attributes of the Gen4 pistol. Note: LaserMax cannot guarantee alignment on ported, fluted or compensated pistols.