I bought the conversion from R12 to R134a at Kmart for $35. Same kit is also used to refill existing R134a. My car already had R134A, but just needed to be refilled. Main reason I bought the whole kit is it came with all the fittings to do just about any car. I comes with the oil, 3 cans of R134A, and various fittings. My car has a leak, and needs to be refilled once a year. At $5 a can its a lot cheaper to fill it up once a year than get the leak fixed. If you decide to do it make sure you read the instructions VERY carefully, and follow them exactly.