There is a variety of different plug cutters in the range, depending on the diameter hole that needs to be plugged.
The plug cutter is measured on the inside diameter. Always make sure that the hole is drilled to correspond to the correct plug cutter.
The benefits of using plug cutters:
The same wood can be used to match with the current timber.
The grains can be alligned to hide the plug even better.
Excess offcut timber can be used to drill the plugs.
Plug cutters can be used to hide imperfections in wood.