Acerbis auxiliary tanks mount on the front forks in place of the front number plate/headlight. They carry extra fuel to increase fuel and fun range! Included mounting kit secures them to most front forks. The included siphon kit integrates the auxiliary tank with the bike%u2019s main tank, allowing fuel to siphon from the auxiliary tank to the main tank while riding; there is no need to stop. The siphon kit drains the auxiliary tank completely before the main tank capacity is used.