Bead chain eyes are a very classic way to add weight to a fly while also giving it a pair of nice eyes. This is used extensively on legendary coastal flies like Frede, Slagteren, Frede with Blood Vein, Magnus, Polar Magnus, and many others. There are many eyes in the package, easy to use, and they give the flies a nice jigging action in the water without making them too heavy even for shallow waters in a fjord. These chains come in various colors and sizes; the most commonly used is M, which fits well on size 4 and 6 hooks, while S is best for size 8 and smaller.