Heating head of the Incubator Systems "Ohio Infant Warmer Systems (IWS)". Models: 2001 from IWS (international), 3000 IWS, 3050 IWS, 3100 IWS, 3150 IWS, 3300 IWS, 3500 IWS, 4000 IWS, 4300 IWS, 4400 IWS, 5000 IWS, 3051 IWS and 3400 IWS.