mini light 1 white SMD led
1 white SMD led: 20 lumens  
material: silicon & PC, with strong magnets 
waterproof (IPX4), size: 15.8 x 3 x 1.7 cm
weight: 18g (batteries included)
power: 2 ‘CR2032’ batteries (included)
it's good for running. backpack and outdoor etc