The Bavaria 25mm tooth iron holder for 12.3 mm receptacle is used in combination with the Bavaria tooth inserts. This holder is on the GS45F air hammer from Bavaria. When the insert is worn out, it can be used again on the other side. Only when the second cutting edge is also worn out do you have to insert a new insert.
There are 3 different inserts available: Flat tooth, fine tooth and coarse tooth.