1. Product choosing Our company have the large quantity of standard products in our stocks. Customer can choose the products according to the acquirement, such as size, technical data and Coating characteristics. Also, we can produce the special optical products according customers’ demand. 2. Product preserving Optical components should be protected with dry situation and suitable temperature without being used. Please clean it with gauze and cotton dipped in special cleaner (20% anhydrous alcohol + 80% ether mixture) 3. Quality assurance Please check out the products when you received with the courier being attendance. Within 30 days after receiving the products, you can contact me freely and provide your testing report if there is something unartificial damage and disqualification technical data. We will be responsible for free charge repairmen, change and return. 4. Payment terms The payment terms can be flexible and can be cash, T/T and Paypal. 5. Delivery terms We can deliver stock products within 7 work days, and within promissory delivery time for customized products.