SHAFT of 9.5 mm (”) diameter with a turned down 13 mm x 8 mm (1/2” x 5/16″) end. Compatible with impeller blades having bores of either 9.5 mm (”) or 8 mm (5/16″) diameter. SHAFT is constructed of passivated 316L stainless steel for enhanced corrosion protection. 460 mm (18″) Length.