OPT series connector has indoor connector built-in, it's connected with screw thread, and well sealed with rubber washers,waterproof grade is IP67. This series includes 3 types, SC, DLC and MPO. It has standard specifications for round (metallic connectors / plastic connectors / waterproofing), square (Type-C, USB / D-sub / floating connectors), fiber optics, high frequency coaxial, modules, etc., and original products for signals / power in round and square. This IP67 OPT fiber connector design uses a screw-threaded. CNLINKO Industrial Circular Waterproof Fiber Optic Connectors: High-Speed Optical Signal Transmission, Robust and Reliable, Harsh Environment Applicable In industrial applications, high-speed and stable optical signal transmission is crucial. Waterproof performance is for IP67/IP68.