UTC Vinyl Rib is translucent, D-shaped, plastic nymph ribbing material. This half-round material is soft and easy to work with. It comes in multiple diameters perfect for creating segmented bodies on the flies you are tying. There is a wide selection of colors in three different sizes. UTC's Vinyl Rib in the medium size (hook size 8-12) is good for crazy charlies, stoneflies and large nymphs. The midge size (hook size 16-20) is good for midges and small nymphs. The nymph size (hook size 12-16) is good for midge to medium nymphs.