Same as the one used on the turn signals.
The emergency signal flasher is required to operate four lights (plus dash) at the same time, the turn signal flasher operates two. They are not interchangeable without a noticeable difference. They are marked 2 lamp or 4 lamp. That's not saying that a new technology would not function for both, but the factory installed flashers were different.
The installation manual appears to show that clip screwed to the back side of the dash down at the bottom - same general area as where the wiring looms is hidden as it crosses over towards the PS door.
That is true.
I have A/C and the unit interferes with where the clip would attach. I am still curious about this as well.
The emergency flasher wiring was installed prior to the air conditioning system.
Good luck finding a clip.
Just for the terminology, there is a nut clip and flasher retainer clip. The flasher retainer is C1TF-13551-A, the nut clip is 45144-S2 (screw is 42127-S2)
Jim