High-security key blank for anti-theft systems. Utilizes sophisticated RF technology. Transponder is embedded in the head of the key with its own unique I.D. number. Using the correct mechanical key with a transponder that matches that particular automobile will enable the car to start. Using the correct mechanical key without the transponder or with the incorrect transponder will not allow the electrical system to operate. The key is cut in the traditional manner on a standard key cutting machine. The owner's manual for the automobile has instructions to program the car to recognize the new key with the new transponder. No. H72-PT: Ford transponder key No. H73-PT: Ford transponder key No. B97-PT: GM transponder key No. B99-PT: GM transponder key No. B103-PT: GM transponder key No. B111-PT: GM transponder key No. H86-PT: Ford transponder key No. TOY43AT4: Toyota transponder key No. TOY57-PT: Toyota transponder key No. Y160-PT: Chrysler transponder key No. B97-PT5: GM transponder key No. B98-PT5: GM transponder key No. B99-PT5: GM transponder key No. B100-PT5: GM transponder key No. B103-PT5: GM transponder key No. PT04-PT5: GM transponder key No. HD106-PT5: Honda transponder key No. MAZ24RT5: Mazda transponder key No. NSN11T2: Nissan transponder key