Our promise 2 years friendly customer service. We will provide quality service at any time. Convenient replacement and return, zero risk purchase. During product use,there are any problems that we can all help you as soon as possible. Product features Stainless steel frame lightweight and durable comfortable to wear. Exquisite cloth pouch for storage and protection. Aspherical lens environmental protection material transparent clear. Computer readers - for frequent use computer,TV,Tablet or mobile phone, can effectively block the screen harmful blue light. 5 pairs in the packaging, For the car, bedroom, office and other places,anytime, anywhere to read.Each pair glasses is carefully selected to ensure quality. Product use common sense Use water to clean the surface stains, soft cloth wipe or naturally dry. Try to avoid use detergent cleaning, will damage the lens surface coating. You can regularly add some oil in the spring hinge, can remain flexible. When used there are any functional problems, in the 2 years warranty period can be replaced for you free of charge.