From The Manufacturer/Wikipedia/People Smarter Than Us:
Meisterstück side-by-side shotguns are light and wonderfully elegant hunting guns; fine representatives of the good old days. The side-by-side arrangement of the barrels is a classical design principle of hunting guns – this principle has been applied in Suhl since the early days. Even if the Merkel brothers were more committed to the over-and-under gun at the start, the Merkel philosophy was soon devolved to the traditional side-by-side gun. An example of this is the aesthetic line of the slim soldered barrels – a trademark of Merkel Meisterstücks.