Some say wear under or over glove!! Under if you want to maybe buy two sets of gloves, tried it didn't work for me!! my glove barley fit over don't want to have to buy second set of gloves to get the one X-Lg!! wore it over the glove works better fit ok! One short ride already shows wear on thin palm material!! Size chart?? I way 165 +or- recommend the Lg. also recommend wearing it over the glove!! Other than longevity of the product "only time will tell" I like it, Like the extra support!! Mind you not wearing on throttle hand!!