Juniper MX2010 Hardware Manual page 444

7. Remove the rubber safety cap from the transceiver and the end of the cable. Insert the cable into the
transceiver.
WARNING:
of fiber-optic cables. Fiber-optic transceivers and fiber-optic cable connected
to a transceiver emit laser light that can damage your eyes.
8. Verify that the status LEDs on the component faceplate indicate that the SFP or XFP is functioning
correctly. For more information about the component LEDs, see the
RELATED DOCUMENTATION
Removing an SFP or XFP from an MX2010 MPC or MIC | 554
Removing an SFP or XFP Transceiver from an MX2020 MPC or MIC
Prevention of Electrostatic Discharge Damage | 794
Do not look directly into a fiber-optic transceiver or into the ends
MX Series Interface Module
428
Reference.