Really well built Goya guru 4.5 that will fit on a 400 mast. Small 5 cent size tear in the luff tube. Good cheap option for the sailor who wants a 4.5 that will squeeze onto a 400 and 160 boom, saves the headaches of purchasing a 370 mast and smaller booms the newer 4.5 require. Mast bend curve is similar to Neil Pryde or Tushingham and so should work on those mast. I have used it on NP mast. Your welcome to rig it up.