CAS 194659-03-5 appears in our catalog under these names: (SP-5-31)-Dichloro(3-methyl-2-butenylidene)bis(tricyclohexylphosphine)ruthenium 97%, GRUBBS CATALYST# M103, Dichloro(3-methyl-2-butenylidene)bis(tricyclohexylphosphine)ruthenium(II), 97%, 97%. Offered by: Ambeed, Sigma-Aldrich, Chemat. Available pack sizes: 100mg, 250mg, 1g.