Why are these listed as R134a ONLY ?

http://www.harborfreight.com/a-c-manifold-gauge-set-92649.html

they look to have the regular fittings on the end of the hoses..

then for R134a they have the adapters...

possibly some not so AC informed copy writer ?

anyone have these and use them for R12 ?

or see what I am missing as to why they are ONLY r134a ?

One of our members is poised to head into New York City and pick these up while on sale...

Please address the specific questions in this thread if you are going to try to answer it...

thanks
Greg

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html