Hi there, I don't think those are rear calipers (as the label on the box states), as they are fitted with flexy brake pipes. The 924S/944 trailing arm suspension design had a hard line pipe with a 10mm ferrule, see picture below:
Attachment:
rear suspension 13.JPG [ 227.36 KiB | Viewed 450 times ]
I don't have a caliper to hand to see how different they may be to front 924S/944 calipers, but I don't think they are rear ones at all. From memory, I recall that the flexy pipe on the front calipers of a 924/944 is in a different position to the ones you have...so not sure they would fit.
Hope that helps a bit, others may chip in with more info....
Best regards, Rhett.