This Simson Battery mudguard taillight LED is equipped with stainless steel mounting materials and has stainless steel metal parts inside. The non-stainless steel metal parts are extra nickel plated. The push button is located at the back of the housing. As a result, this light is absolutely 100% splash and rainwater proof and corrosion can not occur. This taillight can easily be attached to the carrier using a ring wrench. Batteries included: 2 x AAA.