- Two different whistle tones+SOS mode selectable by user - Easy to use : operated by single hand - Hand grip strap design for easier grip on hand. - Addition color ring and Lanyard provided (To replacement of hand grip strap if not in use.) - Special design metal-tubing to reach 125dB+/-5dB loudness. - Handy & Hygienic without blowing the whistle - Suitable for all Sporting events - SOS mode: Give out SOS Morse code automatically when in emergency situations who are vulnerable and need help. - Multi-propose use suitable for: Referee, Coaches, Traveler, Adventurer, Guides, Cheerleaders, Lifeguards, Teachers, Traffic Guides, Dog Trainer... AAA battery. Is not included in a kit, should be purchased separately.