The F-CPL-F12131-FCUPC Wavelength Flattened Fiber Optic Coupler extends the optimal wavelength range to a band of ±40 nm around the center wavelength of 1310 nm. This 1x2 coupler has a 10/90 (10 percent) coupling ratio, and FC/UPC connectors. The F-CPL-F12131-FCUPC can be used directly with the 918D-IS-1 fiber optic detector. It can also be used with the 818 or 918D series detectors with the associated FP4-FC FC connector fiber adaptor and 818-FA connectorized fiber mount. See the Related Products tab for more information.