This Deliverable reports the results of the activity conducted by RSE in 2020 regarding the study of SFCL ( Superconducting Fault Current Limiters ) devices within the framework of the related European project, FASTGRID, which aims to significantly improve the applicability of REBCO conductors to SFCL devices for HVDC ( High Voltage Direct Current ) networks. In 2020, RSE, as leader of Work Package (WP) 4 “Validation and Demonstration Test”, mainly performed tests at a temperature of 65 K on various samples of HTS (High Temperature Superconducting) tape produced by THEVA (including AC overcurrent tests); DC characterizations at 77 K were also performed to measure the critical current of a 5kV/1kA pancake coil made by the partner Supergrid. RSE also addressed the problem of measuring the resistance of the HTS and metallic materials used for the tests. An innovative methodology was specifically developed to calculate said resistance, which was based on the use of a cryocooler that cools the HTS tape “dry”, i.e., not using a cryogenic liquid. This approach allows to reach much lower and much more stable temperatures. On the basis of the developments made in 2019, the study of HTS windings evolved, with a focus on the possibility to create non-insulated windings. This solution appears particularly convenient for the thermal stability of the windings in the event of quench , however it also comes with a complication: current tends to distribute between the layers of superconducting tape even before quench conditions are reached. All these aspects were considered with the collaboration of the University of Bologna, summarizing the main results in a paper submitted to the virtual Applied Superconductivity Conference 2020, which was then accepted for publication. Finally, a series of numerical simulations were performed to study the behavior of different HTS tapes under varying material and lamination layer thickness conditions. This is a very important study for the design of the SFCL 9kV / 1kA device and, in particular, for the choice of the most suitable tape for this type of application.