Gravity Infrared CO2 Sensor V1.1 output voltage high

I received this sensor today, and I got it hooked up to my 5v source. The output voltage is ~3.5v
my understanding of the specs says the operating range should be .4 to 2V.
Do I have a bad sensor? any help would be great. thanks.

https://wiki.dfrobot.com/Gravity__Analo ... U__SEN0219