Scarce WWI USAS 400th Aero Squadron Sergeant's Shoulder Patch

This is a scarce World War I United States Air Service 400th Aero Squadron sergeant's shoulder patch. The patch shows the number 400 over a propeller in a circle.

Circa World War I.

About 4-7/8" height and 3-1/2" width.

Felt patch embroidered with white silk/cotton threads.

None.

None.

This is from a United States Air Service collection which we will be listing more of over the next few months. ebay VAR@VAR

7+ (Very Fine+): The patch has a slight discoloration on embroidery.

As with all my artifacts, this piece is guaranteed to be original, as described.