The tactical olive perdigon is a small and heavy nymph tied for very picky fish.
Perdigon flies was developed aprox 6 years ago by Spanish competitors and are used in clear but fast flowing rivers. These flies has a thin body made of thread or tinsel and covered with UV resin to provide resistance and to give a fast sinking rate compared with a classic nymph. These nymphs should be tied on small hooks , the biggest hooks are usually #14.