Jabsco Genuine Impeller.
# of Blades/Fins : 6
Diameter/Width: 1-1/4"
NOTE: These are the dimensions of a brand new impeller. Worn impellers are usually smaller due to material wear / loss.
Depth/Thickness : 15/32"
Shaft Diameter: 5/16"
Shaft/Drive Type: Single Flat Drive
Insert/Hub Material: Brass
Impeller Material: Neoprene
NEOPRENE is the standard impeller material used in most flexible impeller pumps. It offers a wide range of chemical resistant properites. Temperature range: 45°F to 180°F. 
