Gadzooks! You have simply GOT to hold the new record for absolute least and worst described request for info ever. And on your virgin post too! The term GIGO really applies here.
Now that I've given you some $JTT I'll attempt to guess WTH you're asking. There are both 14mm and 15mm boltheads associated with the A/C compressor attachments. I think. It's been a year or more since I've been near there.
The fact you're asking instead of just putting a wrench on them and taking them off makes me think you are planning on buying some tools to start working on cars, or that you may be using American wrenches that are not fitting correctly. Am I close?
And in the future kindly have the respect to use capitalization, punctuation and correct spelling to repay others for their efforts helping you. Otherwise, you end up giving adults headaches and piss them off remembering all those skills that the nuns beat into them (us), thus causing them to lose interest in trying to help you and then you don't get the answers you were hoping for, or even worse, getting replies like mine you were not hoping for.
But seriously, welcome to the forum newb and good wrenching.