HIVIZ Spark III S.G. Sight.

Read the directions carefully before installing. Take your time installing. This is not simply screw it on and done type of installation. You need to mount the appropriate stud in the barrel, with loctite, and let that cure. You must then test fit screwing the base down onto this stud, removing material from the bottom of the base until it tightens/aligns properly. I recommend using a diamond knife sharpening stone for this procedure. When fitted properly, loctite the base down onto the stud with proper alignment. Let the loctite cure, intall the light tube that you prefer, and you are finished. If installed correctly, this is a nice sight for the price.

they way these mount,you have to sand them down so they line up like they should,i had to sand them so much that i sanded into the pipes and now the sight is not as high as the factory sight is,making the gun shot low,spend the money and buy a factory sight