Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 237)

Using a Remote Switch
You can connect Remote Switch RS-80N3, Timer Remote Controller TC-80N3 (both sold
separately), or other optional EOS shooting accessories equipped with an N3-type terminal
(
).
For operating instructions, refer to the Instruction Manual of the accessory.
1.
Open the terminal cover.
2.
Connect the plug to the remote control terminal.
Connect as shown.
To disconnect, hold the silver part of the plug and pull it out.
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