The Mallard is designed to be the simplest, most cost effective over and under shotgun CZ-USA produces.  It features the standard box-lock frame with the same hinge system used in the more detailed models, but it employs a dual trigger system to keep the production costs low.  It has been a favourite for those who like the functionality and reliability of an over/under with a cost well below most semi-auto shotguns and even some pumps on the market these days.