From the product description, check product page for current description, price and availability:

• DRINK FROM GENUINE OX HORN – Every Viking horn is made of authentic, ethically sourced ox horn (Certified Livestock Certificate), painstakingly selected for appearance, durability, color pattern and shape. Each Norse inspired tankard is unique in shape & color & comes packaged in a medieval burlap sack. It’s time that you chose a drinking vessel as interesting as you!
• PREMIUM MATERIALS – It all starts with the animals from which our horns are harvested. We only select the finest livestock to provide our drinking horns. Even then, eight out of ten horns do not pass our rigorous quality inspections. Finally, all tankards are fitted with a high-quality wooden base and affixed with the strongest food-safe epoxy available. Norse Tradesman leaves no stone unturned!
• HANDCRAFTED WITH CARE – The secret ingredient of a finely crafted mead horn is the care that is put into the construction. Our artisans have been fashioning drinking horns for generations. Each of our horn mugs are hand-selected, hand-cut and hand-polished to near-perfection (we say “near” because as handmade items, no horn is entirely perfect)
• CUSTOMIZE YOUR HORNS – Choose between multiple sizes (Large ≈ 20 ounces / X-Large ≈ 30 ounces), finishes (polished or unpolished) and engraving styles. Note, however, that horn size and color varies. These are 100% natural items!