Heating mantles are preferred to Bunsen burners or hot plates for organic liquids. They provide even heating (no hot spots) and maximum surface coverage for better temperature uniformity. The Series TM spherical flask mantle covers only the flask's bottom half, letting you see its full contents. Larger sizes have multiple circuits for ease of temperature control when a flask is less than half full.
WARNING: chemical spillage, overheating, overloading, and general misuse will greatly reduce service life!