Expert tip: Achieve precise readings of apparent wind angle with the Allen Aerovane Mast Head Mount X 10. Its built-in counterweight prevents "flapping" and unnecessary drag, making it perfect for dinghies and strong winds alike. Simply push the Aerovane onto the rod until you hear a click for easy assembly and removal. Don't forget the A4066 Burgee clip (not included) to attach the Aerovane to your mast.