If you don't like the idea of drinking from plastic, this bamboo water bottle cap is what you need. The stainless steel cap features a top that is finished with sustainability harvested bamboo and has a handy attachment loop. 

• Measures: 1.87" x 2.1"
• Made from stainless steel and bamboo
• Hand wash only 
• Not for use with hot beverages
• Compatible with all Classic Klean Kanteen water bottles