The top and bottom leading edges appear to be some kind of wrapped carbon, whereas the vertical and standoffs are standard pultruded carbon (although from the feel of them it wouldn't surprise me if they are actually glass fibre).
The left & right verticals (G & I) are behind the sail (from the fliers perspective), whereas the central vertical (H) is in front and is joined to the leading edges by the standoffs.
Fittings
Bridle
The bridle is the same on top & bottom and comprises two main pieces - a to c, and c to d (with d being the end of the central vertical spar). The line attachments loops are connected at point c.
The bride is looped around the 'T' connectors on the left & right verticals and the 'T' connector on the central vertical used for the standoffs.
The vertical bridle between x & y has a total length of 76cm, but is comprised of two sections attached via a metal clip. I have no idea why this should be!