I am not sure the A masts are anywhere as low as 7kg, maybe with everything stripped off such as diamonds, hounds etc. My Stealth mast which is seriously old and had serious abuse over the years weighs in at a respectible 12kgs complete with all diamonds, halyards, spinnaker halyards, rotating arm, infact ready for sailing. To loose another 5kgs purely in carbon as the A's have to have halyards etc must mean that they are paper thin.

I know the latest Stealth mast ( by far the cheapest all carbon mast on the market with good quality and a fine track record ) has lost a kilo or 2 with all carbon spreaders and reduction in stay wires sizes etc but not 5kg's <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />