Contigo introduces the CLEANGUARDTM lid cover. When you turn it, the drink reservoir is covered to keep it clean while you also lock the AUTOSEAL® button. The AUTOSEAL® system guarantees 100% spill and leak proof drinking experience by sealing automatically between sips: press gently to drink and release to seal. The mug uses special vacuum insulation technology with double stainless steel walls. Coffee or tea stays warm for five hours, cold drinks stay cool for up to twelve hours.