Important Safety Note
Do NOT take the valve apart without first recovering the refrigerant - you will get a face full of refrigerant!
It is easy to tell these valves apart from regular Schrader valves if you look closely. First, the brass fitting holding the valve is larger than typical Schrader valves. Next, you can see that the top part can be removed from the bottom with a wrench Finally, the head on the pin that operates the valve is larger than the head on a traditional Schrader. The advantage of these is that they open to a full 1/4” hole just by depressing the pin – so you get faster recovery, evacuation, and charging. The disadvantage is that if you want to take the core out for even better flow or if you need to change a leaky valve core, you need their $189 valve core tool. I don’t know how many other manufacturers are using these, but I found out Carrier has been using them on packaged units since around 2006. Here is a link to a web site explaining how these valves work and showing pictures. Coremax Valves
Here is a link to a Carrier Service Bulletin that was posted on HVAC-Talk.com
So a word to the wise - if your valve core tool does not appear to fit - maybe it doesn't. You might have a Coremax valve instead of a Schrader valve.