The Brassie Midge comes with copper or red wire and peacock heads. Two materials that belong on just about any nymph or larva, and the combination here has proven deadly over the years in all types of bodies of water.
It imitates a chironomid or midge pupae that live underwater and are levitating mid-water column. Use this fly under a strike indicator or dry fly on streams, but don't overlook using it in lakes under a small strike indicator as well.
Anyone who fly fishes midges has a Brassie or two in their fly fishing arsenal.