Borosilicate Glass heatproof mouth blown teapot warmer * fits most teapots upto 1.2 litrea (40 fl. oz)with a base of upto 4.4" in diameter * borosilicate heat proof glass ware * comes with a tealite candle to keep te warm. keeps tea warm for hours. * Pls note this fits GLASGOW, MERLIN, and STOCKHOLM teapots only. DOES NOT FIT MUNICH, VIENNA, or INDIGO. (please purcahse CAIRO Warmer for MUNICH, VIENNA)