Blackburn: FRONT AND REAR LIGHTSA simple 'click' of the lens will power up 2 LEDS that pump out 18 lumens of beautiful, bright light that is even visible from the side of your bike for cross traffic. The silicone mounting strap makes it easy to install/remove and works on pretty much any handlebar or bike frame. Two CR2032 coin cell batteries are included and are super easy to replace. 20 LUMES FRONT / 4 LUMENS REAR IP-65 WATERPROOF Ingress protection rating or ‘IP Rating’, is a techy way to describe the level of water and dust proofness a product has. This light meets the IP-65 Standard, which means is totally protected against dust/grit and fully resist strong jets of water from all directions.SILICONE MOUNT Versatile silicone mount fits diameters from 15-35mm. EXCELLENT SIDE VISIBILITY Built in design features channel a bright hit of light to each side providising visibility to cross traffic. • 70 hours steady / 130 hours flash• (2) CR2032 batteries per light• No tools required• 17 grams front / 20 grams rear