1) The wait time is approx 10 seconds, not exactly 10 seconds depends on the current and voltage differences.
2) This 10-second time delay relay module box is measured at 1.65" x 1.25" x 1.25", which is almost twice taller than regular relay box. It is possible that you won't be able to fully close the fuse box cover. In this case, you can try to relocate the relay with extension adapter.
3) The time delay relay is polar sensitive, if after install this, the light stop working, please try to flip output wires around or input wires around. (see both the diagram and the video below)