CAS 135649-01-3 appears in our catalog under these names: Methoxy polyethylene glycol succinimidyl carbonate, 97% average Mw1000, 97% average Mw1000, mPEG-NHS, 98%, mPEG-NHS, 97% average Mw1000, mPEG-NHS, 97% average Mw2000, mPEG-NHS, 97% average Mw5000. Offered by: Chemat, Fluorochem, Ambeed. Available pack sizes: 100mg, 250mg, 1g, 5g, 10g, 25g.