What is the purpose of the extra long slot on some toasters?

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toaster My husband makes sourdough bread and these extra deep and wide toasting slots

2-slice toaster with progress indicator As your bread drops into the extra wide and deep slots and the LED shows your progress, you'll feel in control And Best Buy has honest and unbiased customer reviews for Breville - the Bit More 2-Slice Extra-Wide and Deep Slot Toaster

mjm slot Question: Is the toaster deep enough to fit a standard slice of bread all the way to the top? Answer: Yes, it fits standard slices of bread perfectly No matter how finicky your family can get, the Baumann Bread Toaster makes the most of your toast Features & Benefits 4 slice capacity; 3 easy touch buttons