Grant Optima Series Refrigerated Waterbath Circulator, with a GR150 Thermostatic Controller and a R4 Refrigerated water bath, 20L bath size, temp range -30°C to +100°C, PID Microprocessor controller with LED digital display with menu selection, one programmable set point temperatures, acoustic and visual alarms, flow rate 17L/min, digital timer, over-temp protection, cooling capacity @ 20ºC 900W.