Originally Posted by bover
Lots of folks, including me, went for a round magnet over the intake holes instead of nipples/caps and a ball valve. Works like a champ.
To me the good thing about using magnets over the holes is that when I cook I like to feel what part of the bottom area where the coals are burning is the hottest. Then I know that these vents may need to be closed or partially closed if I don't want the temp to get too high.
The other areas that are not as hot I would open more.
With the valve being in only one spot you really have less control.
The magnets can adjust every hole to whatever size opening that you desire and that is good.