SINOSORB® BL 326-S (CAS 1877301-52-4) is a highly efficient, red-shifted benzotriazole light absorber derived from UV-326 with 5-position p-tolylthio modification, manufactured for optical lenses and display films providing sharp UV/HEV blue light cut-off (<390 nm) and high visible transparency. As an ISO certified supplier, we offer this low-volatility absorber for PC, PET, PMMA, and CR-39 systems.