A/C do-it-yourself kit?

I saw a $30 do-it-yourself AC recharging kit at WalMart last night.
Anyone know anything about the kit?

So people refer to them as Wal-Mart death traps. But they're not talking about bodily damage to YOU. The problem is most people overcharge their systems. R-134a is very sensitive to being overcharged. Unlike R-12 that could handle even a full pound overcharge, R-134a can barely handle a 5 ounce overcharge. Worse than that, the more you put in, the less cooling you get. Overcharging actually degrades performance. So DIY'ers routinely add the whole can and that seizes the compressor. You may have been low to start with, but by the time you get done adding a full can and creaming the compressor, you wished you'd have taken it to a pro.