This is a unidirectional tape which means that all the carbon fibres are aligned along the length of the tape. This tape thus has great strength along its length, but not a lot across its width.
The tape is 65mm wide (2 1/2 inches approx) and is 200 grams per square metre which is about 6oz per square yard.
On surefboards it is normally used around the edges of the board to increase the resistance of the edge to scrapes and impacts. It can be used to increase the stiffness of the board by placing one or two pieces in resin on a surface which flexes convexly, putting the tape into tension. Being black carbon, it can look really great too.