The RD6000-1-EXP is a 4-20 mA input explosion proof remote display that can be used in applications where tank level must be displayed in Class 1 Division 1 & 2 hazardous locationsRD625-1-EXPThe RD625-1-EXP is an RS-485 input explosion proof remote display that can be used in applications where tank level must be displayed in Class 1 Division 1 & 2 hazardous locations