Shaners ISO Dun A lifelike Isonychia mayfly imitation for selective trout.

Shaners ISO Dun #12 is a proven dry fly that imitates the Isonychia mayfly, a staple hatch on many trout rivers. With its slim dark body, upright wing, and delicate hackle, it creates a natural silhouette that rides low and realistic in the surface film. Designed for visibility and buoyancy, this fly is especially effective in riffles, runs, and pools during prolific ISO hatches. Durable and versatile, Shaners ISO Dun is a must-have pattern for anglers targeting trout keyed in on Isonychia mayflies. Shop online or visit Drift Outfitters in Toronto for expert advice and fast shipping across Canada.