Since the videos recorded with the device will be periodically re-recorded, it is better to buy a memory card of a good brand. It will live longer and will correspond to the declared speed class. For all the devices in our rating, cards marked Class 10, UHS-I (U1) or V10 will do. There is no need in more high-speed, if only you pay for endurance models like Samsung PRO Endurance, honed for continuous video recording. And one more tip: choose a card with maximum supported capacity (usually 32/64 GB). That way it will not have to work out of shape, and your memory will always contain recordings of several trips.