BTW the stock comes with SX/DX plate, so you either install it for lefty or right hand shooter. Also it will make your M4 front heavy as the stock is only about 300 gr of weight. As you could see it was 2 QD slots installed on sides (in right places) which are interconnected to each other inside. But there is also a third QD slot at the bottom. 2 slots to insert shells as well. These guys are specialized in sport shooters products, which is why I love their stuff.