What are these things?
 

Sorry if this is in the wrong place. I just purchased a used truck that was a fleet lease. It has two half moon shaped things on top of the truck over the driver. They are yellow and probably about the size of a tennis ball. I'd like to know what they are and how to get them off if I can without ruining the paint job. Anyone know? I'll try to get a picture today and post tomorrow. Thanks.

its probably a mount for light bar or amber colored stobe lights but if i could see a pic i owuld be able to tell more