No comment on the brand as one cannot buy R134 in Canada without a course, and small cans are definately a no no...
However, it's not hard to do. Just a few simple instructions to follow. There should be a chart somewhere on the forum about the atmospheric temps, and the pressures to use. Freon is added while the car is running....

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All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic