CAS 30309-80-9 appears in our catalog under these names: Di-o-tolylphosphine oxide 97%, Di-o-tolylphosphine oxide, 97%, 97%, Bis(2-methylphenyl)phosphine oxide, 97%. Offered by: Ambeed, Chemat, Fluorochem. Available pack sizes: 250mg, 1g, 5g, 25g, 100mg.