In this book I describe precision spectroscopy of ultracold Rubidium triplet molecules using lasers to couple states in different molecular potentials. In the present work the states in the triplet ground state potential (a-potential) and in the first excited triplet potentials were studied in detail. These states are of great importance for transferring weakly bound molecules to the ro-vibrational triplet ground state of the a-potential via states in the excited potential. As most experiments start from molecules in their singlet ground state (X-potential), the triplet states were hard to access via dipole transitions and remained largely unexplored. The measurements presented in this book are the first detailed study of diatomic Rubidium molecules in these states.