Zinsco Catalog number has an a dash between letters and numbers, that designates amperage. RC38-20. The C designates that the handles are tied to form a two pole unit. Some have a removable clip to do the same function. In the 1950's this was a very popular brand. They appear all over the USA in older homes, such as This Old House. In later years Sylvania purchased the brand, then later it was Challenger, then still it was Thomas & Betts. Today only a knock-off brand is made by Unique Breakers. Nick names like Magnatrip, QB, QFP, QFB where also part of the Zinsco group. In many cases the bus bar is damaged from overloading. We stock repair kits for some panels, so please call Breaker Outlet for details at 800-321-8998.