KALENDER HOME 6 Pieces Borosilicate Heat Resistant Thermisil Glass Mug, Tea Coffee Cup 200ml Give Feedback 6 Pieces Borosilicate Heat Resistant Thermisil Glass Mug Cup 6 Borosilicate heat resistant mug cups. Luxury thin glass heat resistant mug. It is made of handmade thin glass. It is lighter and more durable than regular glass. It is suitable for use in the deep freezer. It is suitable for use in the dishwasher. It is 200ml x 6 pieces.