Lightweight and compact, flexible neat design and shock resistant. Simple hook and loop fasten system is secure and easy to use. You can set this to either glow or flash. Whilst it is turned off the unit will still reflect. The battery will last up to 150 hours in either mode and is easily changeable. This unit is compatible to a large range of Ronhill apparel. Receive a Free Maxifuel Viper Active Energy Bar when you purchase this item.