the top off kits aren't so bad if you know how to use them, i used one on my blazer and it works perfectly. though the system was low and im sure there is a slow leak somewhere, i will prolly tackle that next summer if needed. though i must admit, the proper equipment is much nicer to use. either way, acklac7 is exactly right, if they don't know how to use it, they should take it into a shop. its very easy to get hurt working with refridgerant if you don't know what your doing, not to mention what it could do to the environment.