Premium Quality & Heavy duty: Experience the exceptional quality of Hack Athletics Premium Shaker Bottles. Made from kitchen-grade 304 stainless steel, they resist odors and stains, ensuring a fresh taste every time. The double-wall vacuum insulation prevents exterior condensation and keeps your water ice-cold for over 24 hours. Built to last, these bottles are extremely durable and easy to clean, withstanding multiple drops without breaking or cracking.