This is a full set of the OEM Florinated Rubber Oil Control Ring O-Rings for a 2-rotor rotary engine (1974-2011). The set includes 8 O-rings; 4 each of inner and outer variety. We have found the stock O-rings are the best in this application. Please do not substitute with inferior aftermarket Viton oil control O-rings. We have found that they fail far too often at very low miles. The factory part is the best available.