Convert Your 9mm Smart Optic Laser Cartridge To Work With Your Favorite 357 SIG!Use the included adapter ring to convert your 9mm Smart laser into a 357 SIG laser cartridge.Simply thread the 357 SIG caliber adapter ring onto the Smart 9mm laser cartridge following the instructions in the included user guide. Install the short safety pipe (2-7/8" or 2.875 inches) with the nut, and you are good to go! Easy installation with no tools needed! SKU: 357SSADK Safety Pipe Instructions PDF