The Siemens Q120DFN is described as a low voltage plug-in circuit breaker, specifically a 20A 1-pole (10kA at 120V) dual function Arc-Fault/Ground-Fault type QFGA2N breaker. This means it is designed to protect against both arc faults and ground faults, which are critical for ensuring electrical safety in residential settings. It is part of Siemens product offerings aimed at providing secure, reliable, and easy-to-install solutions for electrical circuit protection .