• Universal compatibility: Suitable for bicycle handlebars from 22.2 mm to 31.8 mm, ideal for road, mountain, city, and children's bikes. • Powerful sound: Emits a clear and loud tone of 120 dB, ensuring that pedestrians and passersby hear you clearly. • Durable material: Made of high-quality copper with anti-rust and anti-aging coating, ensuring a long service life. • Water-resistant: Perfect for daily use, even in light rain, without worrying about damage. • Easy installation: Switch clip design that allows for quick and secure installation on any type of bicycle.