NEW MODEL KEURIG K-DUO ESSENTIALS REVIEW - 8-17-2025. A FEW THINGS I FORGOT TO MENTION.... THE "RED LIGHT" DISPLAYED ON THE "CUP" BUTTON IS FOR KEEPING THE COFFEE KARAFE HOT. THE TOP OF THE GROUND COFFEE LID IS NOT A WARMER PLATE, BUT RATHER JUST A PLACE TO PUT THE KARAFE SO AS NOT TO BURN THE ALREADY BREWED COFFEE.