A receptacle connector includes a body, a cover assembled outside the body and a terminal module received in the body. A rudder pipe is located in the upper region of the rudder blade with rudder post located therein, wherein the rudder blade comprises two superposed rudder blade sections having different heights whose front nose strips facing the propeller are offset in such a manner that one nose strip is offset to port or starboard and the other nose strip is offset to starboard or port. The engine can be started by the electric machine or a separate starting device. The channel has a generally \u2018u\u2019 shaped cross-section and a first edge and a second edge configured to be positioned substantially opposing a surface. The liner dispenser may contain a fan folded strip of liners or a roll of liners which may be torn off one at a time at perforated lines as needed. Then, the authentication reference information input from each input path is temporarily buffered.