THE OLD BLUE "2UK" RELAY WAS DISCONTINUED YEARS AGO. THIS ITEM IS THE LATEST BLACK 2S VERSION, THAT IS A DIRECT SWAPOUT UPGRADE FOR YOUR FAULTY BLUE "UK" PART AND WORKS BETTER FOR LONGER. THE PROBLEM WITH THE BLUE 2UK WAS ITS A HIGH SENSITIVE RELAY AND THIS WAS NOT A GOOD IDEA FOR A PARKING BRAKE CIRCUIT LEADING TO COUNTLESS FAILURES.