Features: No need to charge, install three AAA batteries to use, low power consumption, and low voltage reminder function. The launcher is equipped with a lanyard that can be hung on the neck or bed and is very intimate. The host has LED light indication, double reminder, and provides convenience for those with weak hearing. The transmitter is waterproof and has a large panel button. It feels good and it rings as long as press the button. Humanized to consider different environments and time periods, set three levels of volume adjustment, the sense of hierarchy, easy to use at night. Help tools developed for vulnerable groups such as the elderly, patients, pregnant women, disabled people, and children. Specifications: Material: ABS Color: red, blue Size(approx): 6.2 x 11.7 x 3.4(host), 4.2 x 8.5 x 1.5 (launcher) Powered by: 3 x AAA batteries (not included) launcher power by: 1 x button battery(not included) Voltage: 4.5V Use range(approx): 80 to 180 m Built in battery Package Included: 1 pc x Host 1 pc x Panic Button Note: 1. Due to the light and screen difference, the items color may be slightly different from the pictures. 2. Please allow 0.5-2 cm differences due to manual measurement.