This Mossberg manufactured green synthetic button with the white printed "S" on the top is the piece that mounts into the walnut stock just behind (under) the safety lever and assists in indicating which position the safety lever is set at. This part is for the model 195K-A bolt action shotgun and is in very good condition with light wear and will likely need an epoxy to help hold it in place. (file photo)

Note: Mossberg model 195K-A shotguns with the following year/serial number have been observed with this part: NSN