Built-in lithium battery: Built into the alarm you will find a reliable and rechargeable lithium battery. The USB Type-C charging method also ensures a quick and easy charging process. High volume alert: With a volume of at least 135 dB, the alarm emits an extremely loud and attention-grabbing sound to both deter potential threats and call for help if needed. LED lighting: The integrated LED light can be used both as a signal function in emergency situations but also as a flashlight in everyday situations where this can come in handy. Flashing Light Function: The alarm includes a flashing light function with a duration of at least 3 hours that both improves your visibility and immediately draws your attention to your location in case of emergencies. Convenient keychain/carabiner: The alarm also comes with a random keychain or carabiner, which adds enormous flexibility in how you can carry and where you can attach it. Specifications: Size: 9.6x3x1.25 cm Material: ABS+ electronic components, built-in lithium battery Volume ≥: 135 (dB) Light function: LED Working voltage: 3.7(V) Work Stream: ≤130 (mA) Light duration: ≥2 hours Blink time: ≥3 hours Alarm duration: ≥1 hour Standby time ≥ 1 year, Charging method: Type-C Battery capacity: 150mAh Charging time: 2h Package includes: 1 x Self-Defense Alarm 1 x Random Color Keychain 1 x Charging cable 1 x Instruction