Adding a visor to an AD truck really improves the comfort of driving the truck on a sunny day. I have used both styles of traffic light viewers and found them to work about the same. Both viewers work the best at night or on overcast days. It is more difficult to see the traffic light on a bright day and when facing the sun. I am using the clam shell type now. It is mounted to the moulding screw as described above. In addition to being functional, viewers are fun and interesting to folks who always want to know what they are.

Stovebolts are good for the heart