... . 2,BWT flow propeller is light weight, high strength, 3. Good anticorrosion etc BWT flow propeller ... fibre reinforced plastics and highlighted by light weight, high strength,and good anticorrosion etc. The excellent frictional ... mainframe reliable, firstly the speed reducer selects a high efficiencyone, the output power is improved, and running ... by 20% or more, along with high reliability flow propeller