SunDair heater models L020 and R020 series have been designed for under bench heater requirements. Blower-equipped models (UB models) work well when used with convection tubes. Fan units will typically have a screen guard attached to them for meeting OSHA regulations. SunDair is built for left (LO) or right (RO) hand positioning of the burner. Please specify which side of the heater you would like the burner to be located when facing the hot air blowing on you.