Troutline Tactical Trout BL Bug No2 is a simple and effective nymph in the same time. The pink collar is an alternative choice when orange color ( a very popular hot color used in nymphs constructions ) is not working. When the fish is shy and do not take the flies or only "taste" them the you should change the fly with a different hot spot. Pink is very effective and strangely not so popular between fishermen but for fish works excellent!