The conversion electrons from the decay of the 35.5-keV excited state of 125 Te following the electron capture decay of 125 I have been investigated at high resolution using an electrostatic spectrometer. The penetration parameter λ = −1.2(6) and mixing ratio |δ(E2/M 1)| = 0.015(2) were deduced by fitting to literature values and present data. The shake probability of the conversion electrons is estimated to be 0.5, more than two times larger than the predicted value of 0.2.