Article number: 5721303034
Size: 10 mm / approx 3/8 in Hook: J:son SS.DF #22
Many mayflies around the globe are approximate 3/8 inches (10 mm) in size. During the dun stage plenty of these will have a transparent, almost dull grey color. And that is why you should have a couple of these in your box.
We do recommend you to use a J:son Swivel for all your fly fishing and all your flies. However, it is necessary to use a J:son Swivel whenever you are fishing a J:son fly in size 1 or 2.