Guyot Designs Backpacker Stainless Steel Bottle, 32-Ounce 18/10 surgical grade stainless steel provides risk free hot or cold drinking- BPA-free Compatible with all industry standard accessories, including most water filters and the Guyot Splashguard and Griplock 2-1/2 Inch wide-mouth opening Perfect for commuting or sports 32-ounce capacity