With bypass loppers, it is also useful for releasing material jamming the blades. The main distinction among loppers is between "bypass" and "anvil" types. The jaws of bypass loppers may be straight, curved, or one curved with one straight. Loppers are mainly used for the pruning of tree branches with diameters less than . Loppers are a larger, two-handed, long-handled version for branches thicker than pruning shears can cut.