Upgrade Motoring Mikuni PHH Universal O-Ring Insulators – Black, 1 Set. For Mikuni / Solex 40 PHH and 44 PHH Carburetor with Mikuni or other aftermarket manufactured Intake Manifolds. 1 Set required per carburetor. 1 Set includes two individual insulators (One Left and One Right Side) and four o-rings. These New Upgrade Motoring Universal Insulators are 1/4 inch thick. Center bore diameter is 44mm. Center stud hole to center stud hole spacing is 72mm. Universal. Precise CNC Machined – Made in the USA. Material is a thermoplastic polymer that is resistant to lubricants, solvents, gasoline and gasohol. O-Rings Temperature Range -20 to 400F (-29 to 204C). This Item is a Superior Quality Replacement for the Discontinued Mikuni Insulator Part #Z70/050. Uses Mikuni O-ring #Z70/075 or replacement alternative Z70/075-R. Part Number #Z70/050-R-BLK.UNI. One pair required per carburetor. Also Fits Most Mikuni / Solex PHH OEM Carburetor Applications. For Solex OEM applications, Please compare images and measurements to your application for confirmation, prior to ordering. Also available in White #Z70/050-R-WHI.UNI.