The Rambler(TM) 30 oz Tumbler is a next-level addition to your rough commutes day hikes or kayak trips and with the new MagSlider lid it&';s designed for easy opening and closing. This tough bottle is double-wall vacuum insulated to keep your water cold (or coffee hot) until the last sip and its 18/8 stainless steel construction can stand up to even the roughest of conditions.