The Cutler-Hammer CH120 SWD 20-Amp, 1-Pole, 120/240VAC Type CH Circuit Breaker is a black colored, single-pole single-throw (SPST) main breaker with a maximum amperage of 20A. It is made of ABS/plastic and metal materials, ideal for electrical applications requiring a 16-30A current rating. This circuit breaker, with a voltage rating of 120/240VAC, operates with an on/off method and is designed for efficient protection and control of electrical circuits in various industrial and commercial settings.