bkr Straw Cap 1L in NA. bkr Straw Cap 1L in NA. Made for use with bkr Soft Silicone Straws (sold separately). Not to be used with rigid straws.. Splash resistant.. BPA-free and phthalate-free polypropylene plastic.. Removable silicone valve for cleaning.. BKRR-WA47. CLCAPCA-T32HT. In 2011, best girlfriends Tal Winter and Kate Cutler launched bkr with a focus on one main concept which in their minds was Beauty 101: drinking water is the foundation for soft, dewy, pretty skin. The clean, addictive, cult favorite, small-mouth, original glass water bottle was sustainable and eco at its core, but it also made drinking water blissful and easy for a change, and people started noticing. A growing obsession with the pretty little bottle resulted in reports that people were finally truly hydrated and, as a result, they were looking and feeling better. And, as it's said, the rest is history.