Our TKWide Straw Cap comes with a stainless steel and silicone straw that will fit any of our TKWide bottles. The included straw is a wider 10mm, perfect for smoothies, and comes with cut-to-fit silicone extender allowing it to fit any size of our TKWide bottles. Silicone straw tip is safe, comfortable and all pieces are dishwasher safe. The cap is backed by the lifetime Strong as Steel guarantee for a lifetime of use from your Klean Kanteen solutions. NOTE: Compatible with TKWide insulated bottles only (with internal threads). Cap is NOT leak proof.