CAS 1621096-79-4 appears in our catalog under these names: TCO-PEG(4)-NHS, (E)–TCO–PEG4–NHS ester, TCO-PEG4-NHS ester trans-cyclooctene-PEG4-NHS ester, TCO-PEG4-NHS (contains 6% Dichloromethane at maximum), >90.0%(HPLC), (E)-2,5-Dioxopyrrolidin-1-yl 1-(cyclooct-4-en-1-yloxy)-1-oxo-5,8,11,14-tetraoxa-2-azaheptadecan-17-oate, 90.0%, 90.0%. Offered by: Iris Biotech, GLPBio, Biosynth, TCI, Chemat. Available pack sizes: 10mg, 25mg, 100mg, 5mg, 50mg, 10 mg, 25 mg, 50 mg.