This CERT Emergency Whistle from Essential Packs is make of durable high impact, Highly visible green plastic and features a CERT Logo printed on each sides. This whistle comes with a rubber mouth guard that insures a tight seal when blowing the whistle and produces a piercing 125 decibels. In addition, this whistle comes with a convenient carabiner which makes it easy to attach to backpacks and key chains. This compact whistle measures 2" x 3/4" x 3/4".