Baker's blade or nibble with wooden handle. Comes with 4 spare blades and a leatherette case to protect the blade and avoid getting cut.
The baker's blade is used to score the bread just before putting it in the oven to ensure that the gases accumulated during fermentation escape where they are needed.
Fit the blade by inserting the curved part of the steel tip into the first and last hole of the razor blade, attacking it from behind.
Change the blade approximately every 2 months in case of regular use or as soon as you feel that the dough "sticks".