****PLEASE SEE ADDED IMAGES SHOWING THE BOTTLE TOP AND THE INSIDE OF THE BOTTLE**** I am not yelling; just drawing attention to new information in the listing; I would have used a bold or italicized font for emphasis and I apologize to anyone who is offended but as I said, working with the tools I have at this very moment in time. There are threads on the top inside where the lid aligns nicely. There is also a small rubber ring to ensure that it is water tight. It can easily be removed for cleaning and I guess one could use it without although not sure about leaks then. I do not know what this rubber material is made out of. I can include a customer care email and WhatsApp if you must know. Additionally, the fair market value price, which I am still charging 10%-15% below did increase so listing has been adjusted accordingly. Elegant copper water bottle that’s perfect for daily hydration. Handcrafted Pure Copper Drink Ware There are many benefits of drinking from a copper vessel; here are just a few: Boosts skin health, bone strength Improves cardiovascular health, blood circulation, and heart functioning Promotes digestion and regulates thyroid gland functioning and body fat Stimulates brain function Brand new/unused. Comes in box great for gifting (or not)!