If you Cast It They Will Come TumblerDouble wall insulated to keep drinks cold for up to 8 hours and also keeps drinks hot for up to several hours Matching slider lid is provided for drinking on the go (except for 16oz Short Tumbler) BPA free and California Prop 65 FDA tested Base and walls of the tumblers are thicker than competing brands making them ~15% heavier and feel more like glass than plastic Insulate longer by approximately 5% due to thicker walls and base 3. 6" x 3. 4" W x 7.