Bromo-PEG-bromide, MW 2,000 is a large homobifunctional PEG molecule containing two bromides. These bromides are good leaving groups, allowing for the PEGylation of a target molecule to occur on both ends of this compound. The inclusion of a PEG linker allows for high aqueous solubility in certain regions of a molecule as well as impacting DMPK/ADME properties of any given API.