All models feature stainless-steel exterior shell, reservoir, and sample tray, resists rust and contamination. Hinged cover lifts to 90-degree stay-open position or can be removed completely. The dual chamber models feature individually temperature controlled chambers. Drain pump is available for 10, 20, 28 and 5/10 dual chamber models. The 20L and 28L digital models have moveable temperature controllers that can be used on the long or short side of unit. Analog baths offer easy-to-use analog control and hydraulic thermostat ideal for fixed set point application. The digital models feature PID control and digital temperature set and readout selectable display, resolution of 0.1.