This is a Gammarus pattern, weighted with thin lead foil tied on a shrimp hook # 12. Super simple fly. Lead on the hook, some antennas or legs made from Coq de Lon, mono for ribbing, Pro Sportfisher Gammarus Shell black on clear coated with Bug Bond UV Resin, SLF Saltwater Dub fluo shell pink and tying thread. That’s it! Tasty! ;-)