Ninebot® PTR User Manual- 7 -The serial number, which is unique to every Ninebot, and the warranty sheet shall be the only identification forgaining free warranty and after-sale service. Please check whether the serial numbers at the above-mentionedplaces are the same, and if there is any absence or inconsistency, please contact your reseller to confirmwhether the product is a qualified one.Please visit www.ninebot.com, and click “Online Service” at the right side of the screen for online service.2.3 Assembly of new NinebotYou can assemble your new Ninebot by the following steps after confirming that all the parts are complete and in good condition.Remember to switch off the power of Ninebot and unplug the charging cable before handling andmounting of any accessory or cleaning of the mainframe.2.3.1 PreparationBefore the assembly of a new Ninebot, you should first find the hexagon wrench supplied with the product in the package. It should bewell reserved for maintenance and transportation in the future. This wrench is made in compliance with the metric standard, so that youmay get one either in your toolbox or from a tool store.It is suggested that you wear a pair of gloves during assembly so as not to pollute or injure your hands.