Benchmark H4000-S Stirrers feature an exceptionally durable, chemical resistant white ceramic work surface. Their space-efficient design (8 X 9 in. footprint), makes them ideal for use on crowded bench tops and inside of bio-hoods. The H4000S 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 have been activated. With a square 7.5 in work surface, they are compatible with a wide variety of popular sizes of borosilicate glass beakers, flasks, bottles and other vessels.