Impeller larger diameter than Jabsco 4528-0001 replacement by Ancor of Italy.
Impeller Specifications

‘(A) Diameter in mm - 40
‘(B) Depth (Blade length) mm – 19
Number of Blades – 6
‘(D) Shafts insert Diameter mm – 10
Shaft type – 1

Impeller Rubber Material - Neoprene
Shaft diameter 10mm
Sherwood 9979, Johnson 09-806B, Jbsco 4528-0001 has 9.6mm shaft, see Ancor AN 2043.