A spray head (10, 31) for a pre-rinse assembly comprising a discharge cover (14, 35) having a plurality of circumferentially disposed ports (25, 47) for discharging water therethrough; an impeller (13, 34) rotatably mounted within said cover (14, 35), said impeller (13, 34) having a plurality of circumferentially disposed fins (21, 42) thereon and a plurality of tabs (22, 44) disposed circumferentially thereof and transverse to said fins (21, 42), said tabs (22, 44) being disposed relative to said ports (25, 47) whereby a respective tab (22, 44) momentarily covers a respective port (25, 47) to prevent passage of water therethrough and from said discharge cover (14, 35) during rotation of said impeller (13, 34)while the other of said tabs are spaced from the other of said ports to allow passage of water therethrough and from said discharge cover (14, 35); and means within said cover (14, 35) for directing at least one jet of water onto said fins (21, 42) of said impeller (13, 34) to effect rotation of said impeller (13, 34) within said cover (14, 35) and for subsequent passage out of said ports (25, 47) as jets of water characterized in that said means includes a cup-shaped diffuser (12, 33) secured to and concentrically within said discharge cover (14, 35), said diffuser (12, 33) having a base (24, 39) spaced from said discharge cover (14, 35) and a circumferential wall (18, 40) extending from said base (24, 39) and abutting said discharge cover (14, 35), said wall (18, 40) having at least one slot (20, 41) extending angularly therethrough for directing a jet of water therethrough into said diffuser (12, 33). a discharge cover (14, 35) having a plurality of circumferentially disposed ports (25, 47) for discharging water therethrough; an impeller (13, 34) rotatably mounted within said cover (14, 35), said impeller (13, 34) having a plurality of circumferentially disposed fins (21, 42) thereon and a plurality of tabs (22, 44) disposed circumferentially thereof and transverse to said fins (21, 42), said tabs (22, 44) being disposed relative to said ports (25, 47) whereby a respective tab (22, 44) momentarily covers a respective port (25, 47) to prevent passage of water therethrough and from said discharge cover (14, 35) during rotation of said impeller (13, 34)while the other of said tabs are spaced from the other of said ports to allow passage of water therethrough and from said discharge cover (14, 35); and means within said cover (14, 35) for directing at least one jet of water onto said fins (21, 42) of said impeller (13, 34) to effect rotation of said impeller (13, 34) within said cover (14, 35) and for subsequent passage out of said ports (25, 47) as jets of water characterized in that said means includes a cup-shaped diffuser (12, 33) secured to and concentrically within said discharge cover (14, 35), said diffuser (12, 33) having a base (24, 39) spaced from said discharge cover (14, 35) and a circumferential wall (18, 40) extending from said base (24, 39) and abutting said discharge cover (14, 35), said wall (18, 40) having at least one slot (20, 41) extending angularly therethrough for directing a jet of water therethrough into said diffuser (12, 33).