CAS 1167575-20-3 appears in our catalog under these names: Azido-peg12-acid, 96%, N3-PEG(12)-COOH, N3-PEG(24)-COOH, Azido-dPEG®,12-Acid, Azido-dPEG®,24-Acid. Offered by: Combi-blocks, Iris Biotech, Biosynth. Available pack sizes: 100mg, 250mg, 1g, 1000mg.