The Alpina Plug In Light II is compatible with the Altona V, Altona, Hackney Disney, Hackney, Brooklyn, Haarlem, and Idol. This practical helmet light provides additional safety in road traffic but does not replace the lighting equipment required by the German StVZO (§67) for bicycles. The light is turned on and off by pressing the cover and offers several function levels. After the first press, the light turns on and the red light shines steadily. With the second press, it switches to a flashing mode. The light is turned off with the last press. The rear light is resistant to spray water at an angle of incidence of up to 60 degrees. A CR 2032 - 3V button battery is included in the delivery and is already installed.