This is a full metal front light made of aluminum alloy with a small body with a light output of 100 lumens. Equipped with a dayflash mode that appeals to the presence of a bicycle even in bright daytime. Handlebar mount type 1 x 0.5W White LED Li-ion Rechargeable Battery (DC5V/300mA) Can be continuously charged without worrying about the memory effect. Charging time: 2 - 3 hours Battery capacity indicator; 5 modes of light/high brightness/flashing/pulse light/dayflash: 4 hours, high brightness: 2 hours, flashing: 18 hours, pulse lighting: 9 hours, dayflash: 3.6 hours, USB cable included for mounting diameter: Φ22.2 - 31.8 mm, Φ26.0 mm, Mounting shim included 0 mm, 0 mm, 0 mm, 0 mm, 0 mm, 0 mm rubber pad. Accessories: L3.4 x L3.4 Width 1.1 x Height 1.5 inches (29 x 37 mm), 2.3 oz (59 g), Product color may look different from the actual product depending Product specifications, logo design, etc. may be subject to change for product improvement. We also cannot answer measurements or personal fit that the manufacturer does not announce.