The RS2 (Rims Semblance 2) is a legendary emerger pattern developed by Rim Chung and trusted by anglers across the world for its subtle realism and unmatched effectiveness. Designed to imitate emerging mayfliesparticularly Blue-Winged Olives and similar speciesthe RS2 features a slender, tapered body, sparse trailing shuck, and split CDC or hackle wing that mimics the final moments of an insect breaking through the surface film. Its low-profile design makes it deadly on selective trout in clear, pressured water.

Best fished during mayfly hatches or in cold-weather conditions when midges and small emergers dominate the diet, the RS2 works well in both stillwater and river systems. Use it solo for sipping trout or as the trailer fly in a tandem rig behind a larger dry or emerger. A dead-drift presentation is key, allowing the fly to ride just under or in the surface film to imitate a stuck or emerging insect.