Sun's Tea (Tm) Ultra Clear Borosilicate Glass Teapot Warmer (Clear) Heat resistant warmer made from ultra clear Borosilicate Glass Specially Blued Aluminum Alloy Heating Plate Fits most teapots up to 50oz with a base of up to 4.5" in diameter (Thin glass or metal teapot only) Dishwasher Safe Work best with Sun's Tea Glass teapot