Q: How to order or how is the enquiry process?
A: There is two way to contact us. By mail and by phone.
Mail: please pending all the enquiries&orders to mail opto@optolong.com or file the requests in the contact form. Your requirement would be respond within 1 hour during 9:00am to 10:00 pm(Beijing time) at working day. 
Phone: phone call is available from 9:00 am to 18:00 (Beijing time) from Monday to Saturday. Phone number : +86-0871-68317717. Fax to our sales using number + 86-087168317850.

Q: How is the payment terms of Optolong?
A: We could accept telegraphic wire transfer and paypal for payment terms.
T/T: 1)100% TT in advance 2) 30% in advance and 70% in balance are available.
Please check with our sales if partial payment is acceptable. 
PayPal: according to PayPal’s regulation.
Note: Credit card and West Union are not acceptable.

Q: How to ship filters with safe way? 
A: Goods delivered via FedEx, TNT, DHL or UPS express with Optolong own safe packing. The insurance is not covered, unless otherwise specified.

Q: How to calculate shipping charge?
A: We are VIP client of DHL、Fedex、UPS. Freight is calculated by them.Based on shipping companies’ charge collection. It would be marked on the proforma invoice for your reference.

Q: Do you accept the OEM service for different type of filters or different size?
A: Yes. Optical thin film coating design are awailiable for bandpass filter, fluorescence instrument filter, astronomy light pollution filter, anti reflection filter, bleam splitter and dichroic mirror. Please check the OEM service we could offer on OEM item.

Q: Could Optolong support on prototype phase sample offer?
A: There is no MOQ requirement for the prototype filters. We even could offer free samples according to the condition.

Q: There is some problem with the product design. Could you help us to resolve the problem?
A: With years of developing, we have much experience and own understanding of coating design according to different applications. There is much we could do for you.

Q: What is your lead time for filters?
A: Standard fluorescence filter, astronomy filter can be sent the same day payment received. Other stock filters with different size can be sent within 7 days after payment confirmed. Normal OEM orders can be shipped within 15 days. Special OEM orders shipment time depends.

Q: How is the complain process?
A.: If there is any problem with the product and contract. Please email to [email protected].