These Corning® hot plates have a durable glass-ceramic Pyroceram® 4 x 5 inch top and offer superior performance and reliability in a low profile, space-saving design. They operate on 100V/60Hz to meet needs in Japan and other locations with similar requirements. -Easy-to-read numbers simplify measurements, and rugged, extra-large knobs provide greater control for gloved fingers. -Hot top indicator light blinks a warning if the top is too hot to touch (>140°F) - even when the unit is turned off. -Built-in holder accommodates optional support rods (see accessories). -Flatter, whiter Pyroceram® top conducts heat more efficiently and evenly. -Built-in holder accommodates optional 4 inch stainless steel support rods