The BlenderBottle GoStak Starter Pak is an innovative way to carry your protein powder to the gym. These durable BlenderBottle GoStak jars feature Twist n' Lock^TM technology to offer a secure seal and customizable carrying options. Plus, these jars are constructed from Eastman Tritan^TM material which prevents odor and staining. These BlenderBottle GoStak jars are also great to use for carrying or storing vitamins, snacks, hardware, and more. Stay organized with the BlenderBottle GoStak Starter Pak.