Would you buy from a vendor who doesn’t know the difference between five inches and five feet?

In the United States  five feet or (sixty inches) may be written as the number five followed by an apostrophe (e.g. 5′).
Five inches is represented by the number five followed by a quotation mark (e.g. 5″).

Adorama knows the Profoto 254712 is five feet in diameter (5′).
Sears and Amazon have their units confused.