The Forest Marshal River series of spoons are larger, longer and more aggressively cupped than most spoons. As their name suggests, they were designed for fishing mountain streams and larger rivers as an alternative to plugs.
They are 3/8" wide and 1 15/16" long, virtually the same length as the 50 mm sinking minnows that are the "go to" lure for many Japanese anglers who fish lures in mountain streams. At 4.8 g, they are also a comparable weight and will cast like bullets with either spinning or BFS tackle.