The 1x2/2x2 Single Mode mini Wide Band Single Window Coupler(SMMWSC) from FOG Photonics is a Fiber Optic Coupler with Insertion Loss 0.35 to 21.8 dB, Bandwidth ±40 nm, Wavelength 980 nm, 1310 nm, 1550 nm, Directivity >55 dB, Return Loss >50 dB. More details for 1x2/2x2 Single Mode mini Wide Band Single Window Coupler(SMMWSC) can be seen below.