The large circumaural G-Cush earpads will fit on any Grado and are easy to install. They greatly improve the comfort for extended listening and for eyeglass wearers. Since they fully enclose the ear, they provide extra stability to keep the headphones from shifting around, especially the heavier 325 series. They provide a bigger sound stage and lessen the in-your-ear effect. There is a slight loss in sensitivity and a slight shift in timbre since the 'phones are positioned a bit further from the ear.