Supposedly a life span promise, but for the money if we receive a calendar year or two away from them we would be happy. Thus far, we like them much better than merino as our feet seem to be to remain drier. Plus they appear to be Keeping up effectively. https://lookwhostalkingdogtoys39517.creacionblog.com/32367535/examine-this-report-on-big-and-tall-socks