The 203-2-1-51-102-5-1-8 is a Type 203 supplementary protector designed for DC circuit protection with inverse time delay characteristics. This device features a DC delay function (-51 designation) with a 1.50-second delay time and a 10-ampere current rating (-102 code), providing reliable overcurrent protection in DC applications. The unit incorporates a rocker handle construction with switch-only configuration (no auxiliary contacts or relays), and operates with standard tolerance specifications of ±0.015 inch (±0.38 mm) for dimensional accuracy. The supplementary protector is suitable for power protection applications requiring precise time-delay response to transient overcurrent conditions, making it ideal for industrial control systems, telecommunications equipment, and DC power distribution circuits where coordinated protection is essential.