Do you want to enjoy a cold shake for longer? Then the Double Wall Shaker by Smartshake is perfect for you. The double wall insulation helps keep your drink either cold or warm for longer than with a regular shaker. You can easily throw this shaker into your bag as you head to the gym or the office. The shaker is leak proof, safe to put in the dishwasher and microwave, and is BPA and DEHP free. Plus you can change up the design of the wrap between the two layers to really make it your own!