Recently we have developed a family of fast Li-conducting garnets via doping with Li7-3xGaxLa3Zr2O12 (0 ≤ x ≤ 0.5) system. The measured bulk conductivities at room temperature are >10-3 S/cm, at least one order of magnitude higher than currently reported materials (unprecedented, to the best of our knowledge as of September 2013), and approaching liquid electrolyte conductivity values. DFT simulations, in-house NMR and microstructural measurements support successful Ga-incorporation into the garnet structure, but the interplay between Ga, Li and proton distributions is crucial to understand this high conductivity. Moreover the corrosion process with moisture need to be understand in this materials for processing purpose and integration into devices. For this purpose we ask for 3 days at HRPD to measure 8 samples at RT under different ageing processes