Polyethylene glycols (PEGs) in general use are polydisperse molecules with molecular weight (MW) distributed around an average value applied in their designation e. g. PEG 4000. https://www.ealisboa.com/super-find-2009-2014-Dodge-Ram-1500-4pc-Bolt-on-Rivet-Style-Spyder-Fender-Flares-hot-value/