M size or L size Both sizes are in stock. For the ideal upper arms you'll want to show off. Designed in detail based on user feedback, it achieves tightening by applying moderate compression, allowing for care of the entire arm area. Solves the problem of arm shaping innerwear often feeling inadequate due to insufficient length. Designed to stay in place, allowing for "while-doing-other-things beauty". #peaubeaute #armsupporter #peuabeaute #koushi-spats (Far-infrared ray spats)