a component that is added to something to improve it

a tubular attachment used to keep stray light out of the lens of a camera

the accordion-like, pleated expandable part of a camera, usually a large or medium format camera, to allow the lens to be moved with respect to the focal plane for focusing.

a constriction at the muzzle end of a shotgun barrel which affects the spread of the shot.

a power tool or equipment attachment that removes tree stumps by means of a rotating cutting disk that chips away the wood.