Oil Pressure Coolant Temp Gauge Fitting Adapter For LS1 4.8 5.3 6.0 Swap M12 M16 ITEMS DESCRIPTION The Necessary 16mm and 12mm Adapters to Replace Female threads are 1/8 NPT. The 16mm and 12mm male threads are the correct metric threads for an LSX engine. Item Specification: Condition: New Applicable models: Fits For LS Series Engine Oil Pressure Adapter Material: Aluminum Gasket Material: Aluminum Include: 1pcs M12x1.5 Oil Pressure Adapter w/Gasket 1pcs M16x1.5 Oil Pressure Adapter w/Gasket