Don't know what this is?
 

I have an 03 hummer H2. On the intake there is the MAF senser. Then after that there is something that looks like a sensor but has no wires attached to it. Written on it , it say "Press to reset".(I pressed the button before i even read it) Does anyone know what it is? Also does anyone know what kind of MAF sensor it is?(hotfire, hot film, vortex?)