DOCTRONIC PRO-K ECU - ADD ONSThis PRO K ecu is designed to also be up gradable. So you can buy extra little add on packs to customize your ecu to do more cool stuff such as * * PRO K ecu must be bought separately * * 1. Logger interface This allows you to log all your data for a certain amount of time onto a USB stick (included) and then play it back to check things like , knock level , coolant temp , misfires , max revs , basically anything. 2. Expansion box This unit allows for