I'm strictly a newbie at dragging a trailer (after a dozen years in a 28' Class C Diesel), but noticed the CIPA Dual-view clampons are a dead ringer for the mirrors I just picked up at WalMart the other day.
Copies? Knockoffs?
All I know about 'em so far is that after the half hour you invest in setting all those mirrors, you can see most of four lanes behind you and I haven't managed to get a wiggle or a sound out of them at any speed I can drive. Also, I'm 6-1, my wife's 5-6 and she doesn't notice any problem with the view she gets...although I got into the habit long ago of setting mirrors a skosh low/inside so we don't have to screw around resetting every time we change drivers.