The 279-2-1REC4-53F-9-9-7 is a two-pole hydraulic-magnetic circuit breaker from the 279 series designed for DC applications with long delay protection characteristics. This unit is rated for a maximum voltage of 160 Vdc and a maximum current of 100 amperes, utilizing the hydraulic-magnetic principle for accurate and reliable circuit protection. The breaker features a long DC delay curve (53F) with trip time delays ranging from 100 to 900 seconds at 125% rated current down to 0.009 to 0.09 seconds at 1000% rated current, providing flexible protection for various load conditions. The unit includes 1/4-20 stud terminals for back connection and is designed for industrial applications requiring dependable branch circuit protection in control systems and power distribution panels.