I owned a set of the strap on cheap & nasty mirrors, and they made my mirrors (Triton) fold in whenever a truck went past. Invested in a set of Milencos. The build quality is pretty good. They don't fit the Triton MR mirrors particularly well (not enough room between the mirror and the housing), but do hold somewhat. Note to all - recheck the mounting bolts after a bit of a drive, because mine loosened and fell off while driving - lost forever, and Milencos aren't cheap to replace.

Aero 3 Extra Wide Towing Mirrors, well priced, and appear very well made. Light weight and aerodynamic shape will hopefully prevent highway "blow back" experienced with other mirrors only attached to existing mirrors. Only used for one short distance holiday, very easy to attach and adjust. Preferred to, but not quite as clear as previous larger Aussie Truck style ratchet strap mirrors used, so if I was to purchase again might try the larger Grand Aero model, considered this time but was worried about the potential of "blow back" (have lost mirrors in the past after being blown back).

Great towing mirrors. Easy to put on and stay in place. No vibration or movement. Also have plenty of adjustment to ensure you are getting the best view.