I thought my backplate was OEM, though it could be aftermarket from one of various manufacturers. One tends to acquire a lot of aftermarket parts & accessories for the Scorpion to fix its various ergonomic niggles from the factory. My backplate is fairly thick and has QD sockets on either side, which is handy. Hand guard is a Midwest Industries aluminum M Lok forend with a Magpiul M Lok / QD adapter. QD swivels with M Lok adapters should work with the plastique OEM hand guard, which is also M Lok, as I recall.