10mL Glas-Col Micro Heating Mantle, Spherical, 20 Watts, 30 Volts. The Glas-Col micro mantle provides precise heat control for small spherical flasks. This mantle is used extensively in analytical work and in purification of research products when only small samples are available. Supplied complete with a 3 foot, 2-wire cord and locking connector. NOTE: Due to the voltage of the micro mantle, a variable voltage transformer is required.