The F4M-CIR from Fiberon Technologies Inc is a Fiber Optic Circulator with Insertion Loss <0.8 to 1 dB, Wavelength 1310 nm, 1550 nm, 1064 nm, Isolation >40 to 50 dB, Return Loss >50 dB, Optical Power 500 mW(Power Handling). More details for F4M-CIR can be seen below.