1.Feature of high propulsive efficiency. 
2.Low noise. 
3.Well operation. 
4.Anti-wind for propeller.

The data of the  850MM diameter boat propeller: 

Propeller diameter :850mm

 Blade:4

Turing direction: Left and right

Weight: 61kg

Material: Nickel Alu bronze( Cu3)

Pitch:811mm

Expanded area ratio:0.83

The certificate of ABS,BV,CCS,DNV GL, KR, LR, NK and etc are availabe.