Our wooden tumblers begin with pre-fallen urban lumber from yards and parks. Each piece is then artisan handcarved, flame-toasted on the inside for sealing and flavor enhancement, and finally sealed with our SpoonButta olive oil+ beeswax blend. For cold/warm beverages only, not for use with hot beverages. Each holds approximately 5.25 fluid ounces. Care; Hand wash only and re-oil weekly (preferably with SpoonButta or another olive oil and beeswax blend)