Xiaomi e scooter 4 pro 2nd gen abe July 8, 2019 16 32 64 128 Xiaomi electric scooter 4 pro 2nd gen e-scooter abe Scooter xiaomi 4 pro Scooter xiaomi 4 Xiaomi scooter 4 ultra test E scooter xiaomi pro 2 Xiaomi pro 2 vs pro 4