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Sea to Summit says:
The AlphaLight Cutlery uses a durable aluminum combined with a sleek-yet-strong shape to create an extremely lightweight utensil at a surprisingly affordable price. By hard anodizing the aluminum it forms a kind of 'exoskeleton', so the utensils can be slimmer and lighter. This hardened shell also encapsulates the aluminum, to eliminate the risk of the alloy leaching into food.