This is a top cocking upper receiver with adjustable front sight and your choice of 9mm or 45acp barrel. By default these uppers come without the barrel being pinned in place. As an extra option, you may have your barrel pinned in place to avoid the barrel backing out of the upper receiver. Please select pinned or non-pinned and barrel size from the options below. This product is just the upper with no bolt. This item is a special order item, please allow at least two weeks for shipping.