S-LSA – special light sport aircraft, is a factory build, ready to fly light sport aircraft that meets Federal Aviation Administration (FAA) approved ASTM international standards. Therefore, S-LSA aircraft is different from Part 23 aircraft (FAA design and certification standard for general aviation).
A light sport aircraft (LSA), is a small aircraft which it meets Federal Aviation Administration – 14CFR parts 1, 21, 43, 45, 61, 65, 91 date affective as of September 1st, 2004. The light sport aircraft must be weight less than 600 kg (650 kg for Seaplane) and are heavier and faster than ultralight vehicles include airplanes, gliders, balloons, powered parachutes, weight-shift control aircraft, and gyroplanes.
For more information please visit EAA (Experimental Aircraft Association) site: https://www.eaa.org/