The photo shows the Ford part number and below that the manufacturer (Suspa) nomenclature.
View attachment 46537
"540N" is the extension force. 540 newtons/120 lbs.
"47/10" is the manufacture date. In this case week 47 of 2010.
I installed these in 2012 and they were marginally okay for five years.
Howard did some research too. He measured compression force of two new non-OEM struts at 90 lbs each, and two original OEM struts at 90 lbs and 70 lbs. Compression force is typically about 10% greater than extension force. In other words, all four are substantially weaker than spec.
An engineer also told him "They do lose 2-3% of their output force per year, as do all springs. If you’re getting old springs, they’re going to be weaker than they were when they were new."
Much ado about nothing? Not if you've seen the clamshell blown shut by a gust of wind. Picture that at a car show with a spectator leaning over the engine.