A combination cap is a form of military headgear worn with dress uniforms. It has a crown, a band and bill (peak in British English). In Britain such caps are usually known as peaked caps or (in the British Army) service dress caps. In the United States military, they are commonly known as service caps.
The crown is one color, often white for navies, sky blue for air forces, and green for armies, and may be piped around the edge in a different color. The band can be one color, often black, or can be striped. Most caps have some form of cap device (or cap badge). For United States Navy officers, for instance, this is a silver federal shield, above two gold fouled anchors, crossed, with an eagle perched on top. In the British Army, each regiment and corps has a different badge. The bill is short, and in newer caps, a shiny plastic.
These hats are often disliked because of their bulk.