The product descriptions list the fangs as being made from plastic (see the product details for any more specific material information).
Most listings are aimed at adults and are labeled as 'Adult General Sizing'; at least one listing indicates 'Men’s' sizing. If you need a specific fit, check the product listing or size label for details before purchasing.
The sets are designed to be fitted by heating Friendly Plastic Pellets in hot water, pressing the softened material into the fangs, and then fitting the molded fangs over your teeth according to the included instructions.
They’re described for horror, zombie, and vampire looks and are promoted as suitable for trick-or-treating, haunted houses, costume parties, and other Halloween or cosplay events.
The product descriptions state each set is sculpted by a Hollywood FX teeth specialist; the soft, flexible plastic teeth are painted to show detailed, monstrous effects.
No — the product details list 'Battery: No Battery Used,' so the fangs do not require batteries or an external power source.