These heating mantles are made of rolled aluminium body. 
The heating element is flexible, insulated and anchored securely in glass fabric. 
Heating mantles are used to uniformly heat various glassware vessels such as flasks, by placing them directly on the heating element without substantially increasing the risk of glass shattering. 
The temperature can go upto 350°C, controlled through energy regulator.

Rating:
150 W, 200 W, 300 W, 450 W, 60 W, 600 W

Capacity:
100 ml, 1000 ml, 2000 ml, 250 ml, 50 ml, 500 ml, 5000 ml, 3000 ml