Magpul Mossberg Receiver Sling Mount - Black - The SGA Receiver Sling Mount is a connection point for the Mossberg 500/590/590A1 SGA Shotgun Stock and one-point clip-in style attachments such as the MS3 Paraclip, the HK hook, ITW MASH hook, and others. Made from precision cast steel that is Melonite treated for wear and corrosion resistance. Dedicated fit for the Magpul SGA Stock, the Receiver Sling Mount can be installed on either the left or right side of the front of the stock.