An earplug includes a plug portion, a handle portion, and a metal-made hollow round tube. The plug portion includes a plurality of domed flanges and rearward extends to a front end of the handle portion. The handle portion extends rearward by a predetermined length to internally define an axially extended hollow bore with an end cap externally formed around a rear end of the handle portion. A radially inward extended flange is formed in around the hollow bore near the rear end of the handle portion. The metal-made hollow round tube has two open ends and is fixedly embedded in the hollow bore of the handle portion near the end cap in the process of manufacturing the earplug. The flange in the hollow bore prevents the metal round tube from moving out of the hollow bore.
