Slr Guide Forum How Do You Read And Interpret The Footage And Aperture Guide On The Back Of An Electronic Flash?

How do you read and interpret the footage and aperture guide on the back of an electronic flash? - slr guide forum

I have a digital SLR camera, I bought a flash. I do not know how to read the GUID in the back. Promaster is flash the FTD5400. It is also the case when the tour of the extent of the lens?