Tech info: you may have wondered what the +1 value means for the bodyshell height on the X4 set-up sheets. It refers to the different plastic holders that come with the bodyposts. They are optional, and come in three different heights for fine tuning of the bodyshell height in both front and rear. 0 is standard (kit).
The o-ring refers to the shock o-ring, 972030, which is approx. 1.5mm thick.