Platform: 19 x 19cm (7.5 x 7.5 inches); dimensions (W x D x H): 8 x 9 x 4.5 inches Electrical: 120V, 60Hz; control: quick adjustment knobs Features an exceptionally durable, chemical resistant, white ceramic work surface Space-efficient design makes it ideal for use on crowded bench-tops and inside bio-hoods Compatible with a wide variety of popular sizes of borosilicate glass beakers, flasks, bottles, and other vessels The Alkali Scientific™ H4000-S Magnetic Stirrer features an exceptionally durable, chemical resistant white ceramic work surface. Advanced microprocessor controls with convenient turn knobs allow quick, precise adjustment and maintenance of speed and temperature. Safety indicator LED’s on the front panel indicate when the stirring functions has been activated. With a square 7.1 in work surface, all three models are compatible with a wide variety of popular sizes of borosilicate glass beakers, flasks, bottles and other vessels.