For lower left molar subgingival with slightly festooned beaks. The
projection on the buccal beak slips into the furcation. Paired with 31.

For lower right molar subgingival with slightly festooned beaks. The
projection on the buccal beak slips into the furcation. Paired with 30.

For upper left molars with flat beaks, paired with 43.

For upper right molars with flat beaks, paired with 42.

For buccolabial molar furcations with slightly festooned beaks.
Enables to press down the gingiva.