On my 06 stratus the a/c was not blowing cold so I got some of the dye to check for a leak and the leak is at the compressor where the hose connection is. I purchased one of the o-ring kits and after picking what looked like the right size it still leaks in the same spot.

Does anyone know what size o-ring I need to buy? the dealer will only sell me a pack of 5 for $30 and not tell me the size I need.
If you look down at the compressor it is the hose on the drivers side of the compressor. From the pic on rockauto it is the discharge line.

Thanks for any help

Travis