Same great Nautilus "Tuning" air horn, but without the mounting kit or instructions;
No Miata specific mounting bracket
No wiring pig-tails (extension wires to connect to factory connections - plug & play)
No installation instructions, lock nut, washer or 20 amp fuse.
NOTE: This horn is being re-designed by the manufacturer. They are adding more waterproofing. Anticipated availability is March of 2013. Pricing is To Be Determined, but will likely be about 2X the standard Nautilus horn.