The Cherenkov Telescope Array project is the next generation of ground-based very high energy gamma-ray instrument. It will serve as an open observatory for a wide astrophysics community and will provide a deep insight into the non-thermal high-energy universe. The array for the southern observatory will consist of about 4 large, 25 medium and 70 small size telescopes.
The small size telescopes (SSTs) will provide the sensitivity to the highest energies between a few TeV and 300 TeV. Three concepts of telescopes have been proposed to be part of the SST sub-array. If they differ by their design and some of the technological choices, they all propose to use silicon photo-multiplier sensors for their camera. Two of them will use a Schwarzschild-Couder optics with two mirrors dishes, ASTRI and GCT, while one will use a single dish Davies-Cotton optics, SST-1M.
The contribution will focus on the design and performance of the existing prototypes inferred from laboratory measurements and observation campaigns. An insight on the expected physics performance based on Monte Carlo simulation will be presented too.