Electric eye sensor for automatic openers

Does anyone know what the max height is for the electric eye sensors for an automatic garage door opener?

From what I know, most manufactures recommend the eyes be placed 4-6 inches above the slab.

http://www.dasma.com/safetygdopeners.asp
The Six-Inch Rule. The photo eyes mentioned above should not be installed higher than six inches above the garage floor. If the eyes are installed higher, a person or pet could get under the beam and not be detected by the photo eyes.

Thanks guys, I appreciate the help.

I want to see 4-6 inches and nothing higher.

Children have been killed due to this feature being improperly installed or not installed at all.

http://www.cpsc.gov/CPSCPUB/PUBS/523.html

http://www.garagedoorenterprises.com/safetyFactSheet.html

8-9’ AFF, but as others will tell you “Follow the Instructions”

Interesting statement from the website Safety Fact Sheet above…

"If your opener is older than 1992 it needs to be replaced. "

Just a tiny bit off of the original subject. When checking garage door and openers, also check to see if the door is counterbalanced. I find far too many doors that will close like a guillotine when the safety release is pulled.

When people ask me about this, I make a quick demo with a 1/2 filled plastic coke bottle and let gravity do its thing. Opens a lot of eyes.