Socket ID please

[dngrmse]

Hey guys, can anyone identify the manufacturer of this socket? Just curious as I have never seen this mark before. There is a sideways trapezoid on either side, and aside from that, no other markings.

 

[Ole Slewfoot]

It's a about 7/16 ID across the nut flats.







scroll down almost 1/2 page
http://alloy-artifacts.org/duro-indestro-p3.html

 

[Oldtuleguy]

Duro

 

[dngrmse]

Thanks, always good to know.