The Cherenkov Telescope Array is an observatory dedicated to very high energy gamma rays with
unprecedented sensitivity between 20 GeV and 300 TeV to be installed on two sites: Canary Island
La Palma and Paranal Chile. Three telescope sizes will be used to cover the entire energy range.
Two different telescope designs have been proposed to cover the intermediate energy range from
150 GeV to 5 TeV. One of the proposals is based on the traditional single mirror Davies-Cotton
design, with two different camera concepts with different detection and processing schemes are
under test. Another innovative design based on a dual-mirror Schwarzschild-Couder optics has
also been developed and is under test in Arizona, USA. In this talk, the different concepts and the
status of the prototypes will be presented.