It is a small plug with a flat top and pointy spike with an o-ring on it. It just presses in the top. The o-ring seals it and keeps it in place (except not yours). I have a photo of it but don't know how to post it. You have a fork with 'Motion Control' damping. You can adjust the floodgate with a hex wrench. This is the amount of compression you have when you lock out the fork. Even though it is locked out it will still compress a little bit on big bumps. You can adjust that little bit of 'slop' through that hole.