• Set is designed for the L5P Diesel engine with two tank caps
• One cap is located on the side of the tank (Vented) with right-hand threads
• The other is located on the top of the tank (non-vented) with left-hand threads
• GM designed this to eliminate any chance of installing the non-vented cap where a vented cap is required
• O-rings on the center core seal off the tank vent port for proper testing
• Compare to GM factory tool GE-52098 & GE-52098-A
(California Prop 65)