3,4-Dibromo-Mal-PEG2-Amine TFA salt is a PEG linker containing a dibromomaleimide group and a primary amine. The dibromomaleimide group allows for two points of attachement because both of the bromine atoms can be substituted. The primary amine can react with carboxylic acids, activated NHS esters and other carbonyl compounds. PEG linkers are hydrophilic moieties, therefore the attachment of a PEG linker to a compound increases it's water solubility properties in aqueous media.