I just bought a used Surface Pro 4. I want to play Blu-rays on it from an external disc drive. (Portable blu-ray "players" are a joke because the screen quality is commensurate with the resolution.) Many users report that such external drives do not work without being powered from a dock (another expense). A few users report that the LG model CP40NG10 does work with the Surface Pro - but there are no drivers for Windows 10, so it might have worked four years ago, but not necessarily now.