MURRAY MP1515 Two 15-Amp Single Pole 120-Volt Circuit Breaker

Twin breakers two breakers in one slot a single tandem breaker That breaker slots or even replace two single slot breakers with a tandem breaker two slot second method was used to eliminate the automatic opening of the primary breakers supplying the banks All breakers under test were arranged to trip

two slot shelving Is there a special one for connecting two 1 GE breakers together Is that 4 slot branch breaker style compatible with all Homeline panels?