S. E. Eby Co. Pinback Unknown if DUI

[TCSchultz]

I found this pinback badge made by S.E. Eby Co. of Philadelphia mixed in with a lot of pre war DUI DI's and can't ID it so not sure if it's one also or something else.  It measures @ 1 1/4" in height and 3/4" in width with blue enamel for the stripes and the winged star background.  I'm hoping it's an early Army Air Corps DUI but can't find it anywhere.  Thanks in advance for any responses. 

[Airborne-Hunter]

This is an aviation unit.

[tredhed2]

99th Air Base Squadron 

[patches]

How was it actually worn, like above like this?

 

Or like this?

[TCSchultz]

Thank you for the identification and based on that I found another post here in the forum where someone else had the same DUI and it was ID'd to the same unit. Couldn't tell you which way it was worn but as the pin goes the long way I would think top photo would be correct as it would look better that way. 

[FlyNavy02]

The late Jay Massaro illustrates it as in the top photo in his book on AAF DUIs.

[patches]

Thank you TCShultz and FlyNavy02.