ECones, yes, as was said my mirrors will extend about 3" more by pulling on them. I've not even bothered doing that when towing, as I can see just as well as I did with my old 97 F150 with the CIPA slip-on mirrors. The CIPA's were very good and I used them for over 12 years and no complaints at all with them.
My F150 is a daily driver and I love the tow mirrors for daily driving.. I can change lanes, merge, backup, etc without even needing to look over my shoulder.. Just check the mirrors and I can see right up to my door with the "fish eye" mirror.
They do stick out a bit and I'll fold them in when in tight parking situations, but for the most part, I leave them out.
Good luck! Merry Christmas.
Mitch