With a nice loud whistle you're sure to be heard but listen, my friend, may I have a word? If you want someone's attention, you don't have to be tense With this flashing red whistle, you'll engage more than one sense!! To activate simply twist the battery pack on the top of the Red Flashing Whistle. The lit whistle will flash red leds, this is the only light function. Each red whistle comes with a red lanyard. Dimensions: Length: 2.78 in. Width: .62 in. Lanyard: 36 in. LED Colors: Red Red Flashing Whistles include 3 replaceable AG13 Batteries.