The OPI Nail Envy Nail Strengthener Tri-Flex Technology is a liquid formula containing active ingredients such as Biotin, Vitamins A, C, and E. With a volume of 15ml, this nail strengthener is designed to provide enhanced durability and flexibility to nails. Manufactured in the United States by the renowned brand OPI, this boxed product is perfect for those looking to improve the condition and strength of their nails. With a long period after opening of 18 months, this nail strengthener is a reliable and effective choice for nail care enthusiasts.