This custom bkr straw cap is made for use with the bkr soft silicone straws only (no rigid straws please, it's a safety thing). It's made with the same BPA-free polypropylene as the caps you know and love with a clear silicone valve to hold your straw.

Cap with sheer silicone valve for straw that fits 250/ 500mL bkrs

2" x 2" x 2"

To use it you'll first screw the cap onto the bottle, then insert the straw through the clear silicone valve.

Polypropylene Plastic

Dishwasher safe on top rack

BPA-free, Phthalate-free