Additional Cytronex bottle - contains system electronics and 198Wh Cytronex Lithium Ion battery (2 packs of 99Wh each contained in equipment). Please note this item needs to be ordered from a customer account that contains at least one Cytronex unit - the bottle will be set up the same as the unit originally ordered. Please note also in your order the current setup of your C1 (UK/Europe/USA, derailleur or hub gear, whether you want us to change default power levels and to what percentages for each colour, plus the wheel size). Thank you.