It is, however, possible to simultaneously measure or specify L and any one component of L ; for example, L and L z. This is often useful, and the values are characterized by the azimuthal quantum number (l) and the magnetic quantum number (m). In this case the quantum state of the system is a simultaneous eigenstate of the operators L and L z, but not of L x or L y. The eigenvalues are related to l and m, as shown in the table below.