Arc fault breakers are designed to detect and prevent damages from arcing caused by damaged wire insulation or a frayed extension cord. All Q Line circuit breakers are one inch wide per pole, compact devices that feature: Quick-make / Quick-break mechanisms, common trip bars, and easy-to-spot trip indications to ensure safety and reliability. AF2 is a called a Combination breaker as it protects against arcs in both parallel and series and meets current NEC standards. The THQL1120AF2S breaker features arc-fault interrupting technology, a short pigtail for easy wiring, 1 pole, an ampere rating of 20 A, an interrupting rating of 10kAIC, and a voltage rating of 120/240V.