It's glass tub assembly allows the user to observe the sample fluidization and assess if the appropriate airflow is being channeled through the solids bed. The M501 can be provided with a variety of drying tub sizes, as well as inlet/outlet filter. It can process samples as low as 200 grams and as high as several kilograms. Drying time, inlet temperature, and air flow can be varied and controlled either via push button on the unit itself or using a PC (not included).