All aluminum, lightweight plunger mute gives a clear, well defined plunger tone. Knob on end allows for easy "between the fingers" holding. Can not be crushed like a traditional plunger (not if you want to use it again, that is). Also known in some cirlces as a "Hat" mute. Best used for big band or section plunger work. 5 inch (127mm) diameter. Made in USA.