100% PURE SOLID COPPER - Crafted for true enthusiast, each copper cup is handmade of EXTRA THICK heavy gauge copper so it can HOLD the cold LONGER, take drops and tumbles in stride, and be durable and strong enough to last and last. The copper mugs exterior is coated with food safe lacquer to keep it looking and shining like new with little maintenance. RAW Copper Interior - We are one of the very FEW offering copper mugs with a TRUE raw copper INTERIOR. It has NO liners or coatings inside. This enhances the flavor of your favorite drinks while promoting ayurvedic health benefits. PLEASE NOTE, the raw copper INTERIOR can tarnish! To keep looking like new Wright's Copper Cream works like magic. After each handwashing of your mug, DRY completely and you can keep tarnish at bay! STRONG RIVETED COPPER HANDLES - Each copper mug has riveted handles a process that is time consuming, complicated, and expensive, so why do we do it? Its authentic like the originals and we make copper mugs that you will enjoy for MANY MANY years. We wouldn't have it any other way. HANDCRAFTED BY SKILLED ARTISANS - Each of our copper cups are handmade with care and attention by talented artisans making each copper mug unique. The traditional forming and hammering technique are on display as are the carefully shaped lip, the straight or curved body, the size and curvature of the handle, and stamping the bottom with the Copper Mules name so you know its authentic, and you know it will last! LIFETIME GUARANTEE - We work tirelessly to design and deliver the finest copper mugs possible at the best price possible. We STAND behind and believe in everything we sell for as long as you have it. If you ever aren't 100% satisfied with your mugs just let us know and we will provide a replacement or refund.