One Red & one Green dot on the impeller shaft sleeve Aquaflo Flo-Master FMHP / FMCP 0.5hp USA impeller Diameter - 87.5mm, overall height - 92mm, height excluding shaft sleeve - 47mm Vane width - internal - 6.5mm, 6 Vanes (basically the same as an af 91693601 ground down to a smaller diameter)