CAS 9049-93-8 appears in our catalog under these names: Amberlyst? A21 free base, Amberlyst|r A-21, ion exchange resin , Amberlyst® A-21, ion-exchange resin, Amberlyst A21 free base 0.3-1.25mm >95%. Offered by: GLPBio, Thermo Scientific (Alfa Aesar), Thermo Scientific (Acros), Ambeed. Available pack sizes: 250g, 1000g, 1KG.