Live Simply. The MiiR 32-oz Vacuum Insulated Howler is everything you love about the Growler, and less. The Howler keeps cold drinks cold for 24+ hours and hot drinks hot for 12+ hours, no sweat. The Live Simply Howler has Thermo 3D ™ Double Wall Vacuum Insulation Technology. The buckles lid locks in place when opened and the treadless lid doesn't leak.