The image shows an Eaton/Cutler-Hammer BAB1020 circuit breaker. Type: It is a 1-pole thermal magnetic molded case circuit breaker. Specifications: It has a current rating of 20 Amps and a voltage rating of 120/240VAC. Interrupting Rating: It has an interrupting rating of 10kAIC at 240V. Mounting: It features a bolt-on mounting type. Protection: It provides thermal magnetic protection with long time and instantaneous trip functions. Don’t like the price make me an offer You need any additional info message me please Can ship this out to you immediately 
New quality at used pricing, looked and performed like new but for less than half of what my local supplier wanted to charge me! As far as the breaker goes, obviously your looking to add a breaker to an existing panel and you don't really have a choice in the breaker that you use. Other than the difficulty in sourcing them, these are great breakers. Easy to install and works like a charm.