3M Peltor X5A ear muffs. When I ordered them from Amazon, I actually had to accept a click through agreement that said that I was a professional. I thought about it for a second and decided that yes, I am a professional.
Given the weight of the Peltors (15oz) I'm going to look at the behind the ear version. For the Peltor, that's the X5B. The Optime IIIs are also a little lighter (11.4oz). This review says the III is the same as the 105.