Small fits the SpringCreek and TailWater Models. Medium fits the BackCountry Wide, NEW BackCountry, Signature 5-6, 7-8, Everglades, Everglades QC, Bonefish and Salmon Models. Large fits the Riptide, Riptide QC, Spey 8-10 and Tarpon Models. X-Large fits the Signature 9-10, Spey 11-15, Gulfstream and Gulfstream QC Models. XXL fits the Signature 11-12S, 11-12, Pacific and Pacific QC Models. Please note: The SpringCreek, TailWater, BackCountry Wide, Signature 11-12, QC & Tibor Spey models are now discontinued.