UP flashing rear end device, otherwise knowen as a FRED. To be placed on the last coupler of a train. This device took the place of the caboose. If you open this fred with cmp, the flash will stop working because cmp dosen't seem to understand any time less than 1 second and the flash rate is set to 0.5 seconds. To correct it if need be, open it in explorer and in the config file set the frequency to 0.5 and save. This is consistent with what the ccg says is correct but cmp dosen't know it, lol.