The eagle is embroidered with silver metallic gimp on a black cloth. The classic officer breast eagle of the Panzerwaffe des Heeres, it went to all the officer tunics of the ground forces tank crews.
How to sew the patch? Attach the patch to the uniform so that it sits well. Glue the patch or fasten it in another way (for example, stitch it with a thread of noticeable color). Sew the patch by perimeter with small stitches over the edge, use a thread in the color of the backing. Set the needle 2-3 mm from the edge, otherwise the underlay will tear (shag), and the patch will fall off.