Product Features: Dimensions: 2.8x1.5x0.6". Battery Type: 3 LR44 batteries included. Standby time: 1 year. Battery life: 50 minutes continuously. Brightness: 90 LED lumens. Contents: 1 personal alarm, 1 carabiner. You can easily hang it on a keychain or bag. Durable design – suitable for everyday use by individuals of all ages, including students, elderly individuals, children, women, and night shift workers. Integrated LED light provides a bright strobe function activated by a button press. The SOS light alarm keychain is designed for personal safety. A loud 130dB alarm siren combined with the SOS light helps attract attention and deter threats in emergency situations. Note: 1. The alarm is very loud; do not place it near your ears. 2. If the alarm does not sound, remove the screws from the back cover and replace the batteries. Note: Measurements are manually taken; please allow a 1-66 cm variation. Due to differences in lighting and screen settings, colors may vary slightly. Actual product may differ slightly from images shown.