Purchased his unused SP-542 spark plugs on Friday, 22 May 2020 at a killer price. He had them packaged nicely, shipped across the country, and in my hands on Tuesday, 26 May. I'd venture to say I would have had them earlier if not for a 3-day weekend. His price, prompt response/communication, and shipping were second to none. Thanks a bunch @Ecoboost_xsport !