Weight: 250 to 500 g High visibility and reflectivity? LED armbands are clearly visible in the dark and their material can reflect light. So the LED armband can prevent some potential dangers during morning walking, night walking or dog walking. Two Lighting Modes: The light strips have three lighting modes: faster flashing, even glow, you can choose any of them as your preferred mode for outdoor activities. Weatherproof with non-slip stretch band - The running reflectors, with a length of 20-40cm, are adjustable, suitable for most men, women and children. You can wear them on your wrist, ankle and arm. Weatherproof with non-slip stretch band - The running reflectors, with a length of 20-40cm, are adjustable, suitable for most men, women and children. You can wear them on your wrist, ankle and arm. Interchangeable batteries? Powered by two CRV2032 lithium button batteries, the bracelet can work for about 60-80 hours. Batteries can be replaced when the current is low. Where to use the LED armband? This LED armband is a must-have for outdoor activities. You can wear it on your upper arm, wrist or ankle when jogging or walking the dog. You can also pair it with your backpack or bike when hiking or cycling. With highly reflective material and highly visible light, the LED armband can prevent potential danger and ensure people's safety. What are the advantages of our LED armband? Bright lighting. Thanks to the reflective material, our LED bracelet is much brighter than similar products, ensuring safety from outdoors. Best quality. There is exquisite stitching with good nylon material and environmentally friendly transparent PVC material, so the LED armband is practical. The battery is easy to change. Behind the switch button is the battery compartment, it is very open, you can use a coin or screwdriver to open and change the batteries. It's very comfortable. How to use the LED armband? Press once for permanent lighting. Press twice to flash. Press a third time to deactivate the warranty. Note: Do not force open the black battery case. If you wish to change the batteries, be sure to follow the replacement instructions shown in the images.