Collar devices should be what specific distance between the end of the collar wings and the bottom of the device?

1 in.

Explanation:

The U. S. Navy has certainly established regulations concerning the way individuals wear uniforms and collar devices. Uniforms for officers and enlisted staff are different, and their regulations and requisites are different as well. Also, there are more divisions regarding officers, with distinguished rules for uniforms, depending on whether they are line officers or staff corps.