The L on the end is Left side clip 1 Pole 20A Half size, thin type A replacement breaker Plug-in 120V Challenger, Sylvania, Thomas & Betts, Crouse Hinds or Connecticut Circuit Breaker companies all made this breaker in the past. This brand was also made by Thomas & Betts. Originally made by Crouse-Hinds, Murray. Widely used in residential applications. Alternate No. UBITB-A120L
` Breaker Outlet inspects all of our products prior fulfilling your order. New A120L's come with a 1 year warranty. All Re-Certified A120L's come with a 2 year warranty.