The Rutland 503 is lightweight, portable and simple to install, the Rutland 503 is ideal for small yachts and for motor cruisers with low energy requirements. The Rutland 503 Features: Quiet effecient operation Portable and simple to install Safety turbine outer ring protects blade tips Proven long life design Trickle charges from just 5mph wind speeds Mount on 31.7mm internal diameter tube with maximum external diameter of 38.1mm Aerodynamic design for maximum effeciency Performance: Charging commences at just 5mph Rated power 25W at 22mph Delivers up to 60W Net weight: 3.8kg Gross Weight: 5kg HRS regulator recommended to prevent battery overcharge. Mounting kit includes 2M pole, deck & guy brackets.