/lib/udev/rules.d/92-usbrelay.rules is in usbrelay 0.2-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | SUBSYSTEMS=="usb", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE="0660", GROUP="plugdev"
KERNEL=="hidraw*", ATTRS{busnum}=="1", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df",MODE="0660", GROUP="plugdev"
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