MFF04FF1801A50 is a Royal Ohm resistor, a radial leaded, 4 watt, 5% tolerance, metal film fixed resistors. The MFF04FF1801A50 has a resistance value of 18,000 ohms, and a rated power of 4 watts. It is axial-leaded with a 0.472" lead length, and is made of metal film materials. The MFF04FF1801A50 has a 5% tolerance value, meaning that the actual resistance value may differ by up to 5% from the labeled value of 18,000 ohms.