How long is this extension? Also are there any other parts required to extend my stihl km hedge cutter with this item?

I have been and measured this one for you and it is approx 130cm from end to end. There are a couple of different extensions you can use on your machine, you can see them here: https://lsengineers.zendesk.com/attachments/token/8C3aanzdDSPgpNfyIZBDcOeDy/?name=KM85+Parts+Diagram.pdf