CAS 57-13-6 appears in our catalog under these names: Urea, 98+% , Urea, ACS, 99.0-100.5% , Urea, 99.3+% , Urea, ultrapure, 99% , Urea, 99.5+%, Molecular Biology Grade, Ultrapure, Thermo Sci. Offered by: Thermo Scientific (Alfa Aesar). Available pack sizes: 10000g, 2500g, 500g, 100g, 2kg, 2.5kg, 1kg, 5kg.