Do not us them. They came out in a short time. That's were the good stop. The technician was not knowledgeable on the Freon that my system is using. I informed him that I had a leak. After checking the system he informed me that it was due to the service caps missing O-rings. As a automotive technician I try to tell him that the cap are not part of the system and will not cause a system to leak. I tried to get him to do a more executive checks and he told me that it would not be cover under the warranty. So I call the warranty provider to ask them if it was covered and they told us it was. He went outside to "talk with his boss". After a min. or two I went out to see what was said and he was filling the system with Freon (you need to remove the Freon to do a executive system check). At this point I was done. I let him finish then paid him and dusted that they will never come back to my home. I hope this helps in to search.