Electrical breaker panel
"Sylvania" had a couple of different types of breaker panel systems during their forray into that business. One of them was called "Zinsco", the other was "Bryant" panel and breaker system. The Bryant version was eventually taken over by Eaton / Cutler hammer and is now called their "BR" Series (BR for Bryant). Zinsco breakers were / are a disaster waiting to happen and in the opinions of most people, should be ripped out and replaced as they had a tendency to not work and/or catch on fire. Zinsco as a stand-alone company went bankrupt ages ago because of this and Sylvania was unable to rescue them, so they too got out of the business. There are some aftermarket companies selling redesigned versions of the Zinsco breakers, but before wasting money on them, check to make sure your homeowner's insurance policy doesn't have a rider saying that they will not cover any losses from failures of Zinsco (and Federal Pacific Stab-lok) breakers. Some do, and in some jurisdictions you cannot make any alterations or repairs to these panels, you must rip and replace.