CAS 6381-59-5 appears in our catalog under these names: Potassium sodium L-tartrate tetrahydrate, 99% , Potassium sodium L-tartrate tetrahydrate, ACS, 99.0-102.0% . Offered by: Thermo Scientific (Alfa Aesar). Available pack sizes: 1000g, 5000g, 250g, 100g, 500g, 2.5kg.