Trijicon RMR Sealing Plate
Required for use with electronic RMRs (Auto Adjusting LED and Adjustable LED), and recommended for use will all RMR models to guarantee waterproofness on mounting surfaces that do not completely cover the o-ring on the bottom of the optic.
With the sealing plate installed properly between the RMR optic and the mounting surface, the RMR can be submerged up to 66 feet, for at least one hour without leakage.
Made from stainless steel. Weighs 2.8 grams.