In this proposal we propose to investigate the superconducting ground state of the non-centrosymmetric superconductor Ru7B3. Controversy exists over the nature of the superconducting ground state, because of the high Hc2 and the lack of the centre of inversion, it is expected that triplet superconducitivity should exist. However, heat capacity suggests that superconductivity is predominately s-wave and that there may be a smaller contribution which is p-wave. uSR is an ideal tool to investigate this and therefore we request 4 days on the MuSR spectrometer.