The best boom head just got better.  This is an RDM specific boom head that is lighter and stiffer than anything else on the market, and now it's easier to adjust.  The new head from Streamlined will fit a variety of different booms from Neil Pryde, Maui Sails, Simmer, Chinook, Aeron.  The new integrated cleat and lever design, combined with Dyneema rope, make it easy to get your inhaul line adjusted to your mast diameter, and the RDM specific design means no shims to lose.  

Description from Streamlined:
RDM specific aluminum boom head, the most solid connection between your mast and your boom. No loss of power or control from looseness or stretching plastic. Top performance as you can become one with your rig.