Genuine original agitator had a black grooved pulley for the belt to ride on as seen picture # 1 and2 . The improved version the belt rides directly on the wooden dowel picture 3 and so on.  The brush roll  has been revised and improved by the manufacturer. You are getting the picture 3 roller. 

Part# 8192535   8175121 KC84RDCXZ000 2050 2055 20006 20011 C50XDDYOBO47  CENTEC CT-18 41065A  AMC84RCRE00P

Fit:

16.22813203, 116.23812300, 116.23813300, 116.25512500, 116.25615500,  116.25615506, 116.25812503, 116.25813506, 116.25813508, 116.25914505, 116.25914507, 116.52813200, 116.53512300, 116.53513300, 116.53612300, 116.55512500, 116.55615500, 116.55813500, 116.55914507 , 

11652812200 , 11652812201 , 11652812202 , 11652812203 , 11652812204 , 11652812205 , 11652812208 , 11652812209 and more