Designed for cycling to securely fit in most standard water bottle cages Bounce back lid allows for one hand operation Speedflask now comes standard with Bounce Back Lid 20 This lid features a larger release button that protrudes out for an easier touch reference when hydrating on the fly Vacuum insulated Keeps fluids cold for hours 188 pro grade stainless steel Double walled eliminates condensation Easy to clean No residual flavors Wide mouth screw cap makes it easy to add ice NOTE Speedflask is not interchangeable with Speedfil A2 or F2 hydration systems