Coghlan s Six Function Whistle is a versatile tool that has everything you need to stay safe and prepared in an emergency. It features an LED light compass magnifier thermometer and signal mirror all conveniently packed into a lightweight and compact design. The included lanyard and clip make it easy to attach to your backpack or gear and batteries are included for added convenience. Whether you re hiking biking or paddling this whistle is a must-have for any light adventure.