Much like regular command blocks, the minecart with command block is only obtainable using /give. The minecart with command block is used to run commands and travel. A benefit of command block minecarts is that you do not need to give it input from a Clock circuit; for as long as it is powered, it will repeatedly run the command, once every four game ticks (five times per second). The minecart with command block gives a comparator output when it goes over a detector rail.