The 203-1-1-66F-252-L-1 is a Type 203 supplementary protector designed for power protection applications with inverse time delay and magnetic supplemental protection features. This device incorporates a 1.50 second delay time and is rated for 250 amperes at the specified voltage, with a rocker handle construction and U.S.A./CSA certification. The protector features a multi-frequency short delay characteristic (-71 designation) and includes an illuminated handle option for enhanced visibility. It is commonly used in industrial and commercial power distribution systems where reliable circuit protection and controlled trip response are essential for equipment safety and system continuity.