What is a valve core and why do I need to remove it before installing Slime?
When you look inside the top of the tyre valve, you will see a metal cylinder in the very center. This is the valve core. To install Slime, use the black valve core removal tool on the cap of the bottle to slowly twist the valve core counter-clockwise. Allow the air to slowly escape before removing the core completely. After installing Slime, replace the valve core and re-inflate the tyre.