Amine-Tri(3-methoxypropanamide-PEG23-Azide) Methane HCl salt is a branched PEG linker containing three azide groups and an amine group. The azide groups are open for click chemistry with alkynes and strained cyclooctynes like BCN and DBCO. The amine can used as a nucleophile such as in coupling reactions with carboxylic acids. Large PEG spacers improve aqueous solubility and impact ADME properties.