This blind spot mirror simply sticks on to your existing mirror (via its own sticky fixer) and its  tilting convex mirror allows you to position it so that you have no blind spots. I fixed mine in the position shown in the photo and it works brilliantly with no loss of rearward view. (The mirror sticks over the part that shows your reflection).
Next time you see a car about to overtake you check out the blind spot when it disappears from view and  then appears alongside you.
In the split second you dont see the car its possible to pull out for a quick overtake and not even know there is a car alongside you! These mirrors allow you to see the vehicle constantly.
Price is for ONE mirror.