The GUARDIAN is the strongest optic mounting system on the market. TRU-SEAL eliminates the need for an added sealing plate. 0-rings on the mounting screws hold the plate watertight to the slide, sealing out moisture, eliminating corrosion in the mounting threads. Our STUD-LOK threaded stud/nut mounting interface is the most secure system on the market. This provides much longer thread engagement, greater hold down power, with increased shear resistance. SIX BACK-UP SIGHTS SIX back-up sights (BUS) seamlessly integrate into the Guardian Optic Mounting System providing rapid, reliable, and precise target acquisition in scenarios of red dot optic malfunction. Featuring anti-glare, anti-snag and ultra low co-witness design, SIX sights lie inconspicuously in wait until you need to deploy them. Like a wingman when things aren't going as planned, SIX has your six. Product Specifications Model: Guardian+Six Frame Material: 7075 Aluminum Firearm Type: Pistol Mount Type: Glock MOS / Holosun 407C / 507C Footprint Frame Color: Black Compatible With: Glock MOS Includes: Mounting Hardware DISCLAIMER: GLOCK is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. or GLOCK Ges.mbH. Neither Sportsmans Outdoor Superstore nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.mbH. The use of GLOCK on this page is merely to advertise the sale of GLOCK pistols, parts, or components. For genuine GLOCK, Inc. and GLOCK Ges.mbH products and parts visit www.glock.com.