Noninsulated Flexible Duct, 4 in Flexible Duct Inside Dia., 1/8 in Flexible Duct Wall Thickness/ WALL THICKNESS: 0.125 INCHES NOMINAL INSIDE DIAMETER: 4.0 INCHES NOMINAL BOTH ENDS TEMP RATING: -20.0 DEG FAHRENHEIT AND 180.0 DEG FAHRENHEIT END ITEM IDENTIFICATION: 6640015864078 MEASURING METHOD AND LENGTH: 25.0 FEET NOMINAL OVERALL PART NAME ASSIGNED BY CONTROLLING AGENCY: NONINSULATED FLEXIBLE DUCT