Supported leading edge kite (SLE) is a type of power kite used mainly for kitesurfing.
It refers to a C shaped kite leading edge inflated (LEI) kite where the lines which control the angle of attack (or sheeting) of the kite attach to a bridle via a pulley in a similar way to that of a bow kite. Due to the wider range of angle of attack possible, relative to the wind, this system has vastly improved C kites' ability to depower and has increased the possible wind range.
References
Supported leading edge Wikipedia(Text) CC BY-SA