WP Total Hardness Back Catalog number: 54156 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 1616.14-10MG 4-Methyldiphenylmethane, neat, Solvent-neat, Unit 10mg, # of units-1, Cas.no. 620-83-7 Price on request 8452.13-10MG 2-Phenylbenzimidazole-5-sulfonic acid, neat, Solvent-neat, Unit 10MG, # of units-16, Cas.no. 27503-81-7 Price on request PN-53S 1,2,3,5,8-Pentachloronaphthalene, 1.2ml x 50ug/ml, nonane Price on request