[Bicycle Helmet with Detachable Taillight] Bike helmets for men women comes with led back light in the shape of diamond. 3 lighting modes (steady, slow flashing and fast flashing) help people behind you recognized your direction clearly, and provide max visibility and safety while night riding on the city streets. Extra back-up battery is also included. [Super Comfortable Bike Helmets] Aerodynamic and ventilation design 15 vents allow air go through the biking helmet, which is helpful to increase the speed and keep cool during riding a bike. The inner pads is super soft and comfortable, which can be removed to clean. A good bicycle helmets for adults will keep you comfortable, good looking and confident. [Adjustable Fit System] Biking helmet with a standard size, equipped with the easy-use dial system and side straps make this mountain bike helmet adjustable to different head size 58cm-62cm(22.44’’-24.41’’) and fit most cycling riders both men and women. Super light-weighted 270g(0.59lbs) bike helmets for adults will not cause any burden to the rider's head during cycling.