ACDelco® 18213L - Professional™ HVAC Heater Hose Do not use for fuel or oil transfer applications. Installs without buckling, bending out of shape, or straining at the connection for easy installation ACDelco Professional Molded Heater Hoses are temperature rated from -40 degrees Fahrenheit to 275 degrees Fahrenheit (-40 degrees Celsius to 135 degrees Celsius) and can be used for coolant, water, and air applications and are also approved for Marine applications. Acdelco 18213l Professional Molded Heater Hose 63981 1994-1995 ACDelco | Shaheen Parts Molded Heater Hose 18213L Reinforced Rubber. Number Of Branches: 0. Molded: Yes. End 1 Inside Diameter (in):. 5/8 Inch. End 2 Inside Diameter (in):. 3/4 Inch. End 1 Inside Diameter (mm Its diameter ranges from 1/4 in to 1 in to fit different types of vehicles ACDelco Professional, premium aftermarket Molded Heater Hoses are specially designed, factory-molded hoses to fit today’s smaller, tighter-fitting engine compartments. ACDelco Heater Hose 18213L | O'Reilly Auto Parts Less than 500 part numbers cover more than 1,200 applications to maximize coverage and reduce inventory