Our Aftermarket Sherwood 10077K Impeller includes the following:
1pc  Impeller (Neoprene +  Stainless Steel)   12 Blades 

Inside Diameter  1/2" with Square key slot
Outside Diameter  2 - 1/4"
Width       25/32"  

Fits the following:

Sherwood Pumps: G701, M10095G , N10360GX
 M10261G (B) , M10262G (K) Chris-Craft # 16.80-10007 (M10262G)
 
Equivalent to:
Sherwood 10077K, Westerbeke  11764 or 33100, Onan 132-0375 , Sierra 23-2000