Umpqua's Trout Shanks are straight shanks that are perfect for tying "trailing hook" style flies, similar to those commonly used for steelhead. The 20mm size is a fine wire shank which is perfect for tying small articulated leech-type patterns. The 50mm shanks use a much heavier gauge of wire and are ideal for larger streamer patterns such as sculpin or baitfish trout streamers, or even salmon and steelhead flies.