This part is compatible with the following models: N15
10-inch left hub brake auxiliary wheel - inflatable inner and outer tubes (Chengxin 10*2.5 inner tube thickened), outer diameter 243mm, inner diameter 137mm, width 55mm - 2 left and right shaft sleeves - 2 anti-rotation plates - with round cap flange nut - shaft length 127*M12 shaft - crotch size 91mm left shaft sleeve length 11MM, right shaft sleeve length 19MM, black, matching with motor tires