The Pro-1 boom head is fully articulated, so regardless of what height the boom is set at, there will be no excess tension on the boom arms or the mast. It also ensures that if the boom head is not level with the clew, the boom will not pull at the leech or foot of the sail. These carbon booms come into their own in choppy or overpowered conditions - their stiffness resists arm bending, and prevents the rig from distorting and causing you problems!