The item that we are selling is a great find!  This is a new in the package set Oversize 64mm Piston Ring set (1 set for all 4 pistons - enough for 1 complete engine) for the   1969 1970 1971 1972 1973 1974 1975 1976  Honda CB750 Four motorcycle.  This is for bikes using the  64mm oversize pistons on the 812 big bore kits only, not the stock standard bore size. We do have STD. size rings elsewhere on our website as well as 65mm (836 big bore rings) on our website if that is what you need.   This has the 2 compression rings and the lower oil control rings.. everything to get your pistons/ engine running nicely again.  For thickness to compare to your original rings..these rings measure 64mm x 1.5mm 1.5mm 2.5mm. Some 812 kits produced years ago used a thinner top ring..so please check your old set or your piston ring landing to confirm this is correct for your application.   Get your bike up and running again. This is correct for all of the CB750 F and CB750 K models. This will not work on the 1976 CB750A model. We only sell the best! This is a top-quality aftermarket item shipped new in the package. Good stuff if you are riding or restoring or AHRMA racing these cool bikes.  That is it!