Size: 28x4cm Wide range of uses - emergency whistle, compass, thermometer, monitoring rope, LED light, high decibel personal alarm and many other functions play a decisive role in your outdoor travels. Personal Alarm --- can emit 130dB loud sound to attract attention, it can effectively scare away dangerous attackers and seek help from nearby people . Convenient LED lights---a good helper in the dark, emergency light, LED lights in the distance, let you feel comfortable in the dark. Fits All Sizes---Adjustable size allows most wrist women, men and children to easily adjust all wrist sizes. Sturdy seven-strand rope--- This bracelet is made of high quality rope, which is durable and can be used to repair clothes, repair objects, fishing line, hem ostasis and a hammock. Note: Since it is manual measurement, please allow some errors in the data. Thank you for your understanding.