... ,NK certificate. 2.Material: Alloy,Cu,Ni-Al bronze,Mn-Al bronze 3.Ones warranty.customerizd sized Specifications1.GL,LR,ABS ... CCS,NK certificate. 2.Material: Alloy,Cu,Ni-Al bronze,Mn-Al bronze 3.Ones warranty.customerizd sizedFixed Pitch PropellerMaterial: Alloy,Cu ... ,Ni-Al bronze,Mn-Al bronzeSize: as the customers' request. Blade: 3 ...