Nørding Keystone filters are highly absorbent natural volcanic clay pellets that can be used in all types of pipes to help to remove the humidity from the tobacco and the condensation created while smoking. When using Nørding Keystones in a traditional pipe you also “lift” the tobacco a few millimeters from the bottom of the pipe bowl avoiding the tobacco to “block” the airflow in front of the draw hole.
 
If you live in a hot or humid environment, Nording Keystone filters are highly recommended to help maintain a proper tobacco moisture level throughout a bowl.