Symbolic Model-Checking Using ITS-Tools. We present verification toolset ITS-tools, featuring a symbolic model-checking back-end engine based on hierarchical set decision diagrams (SDD) that supports reachability, CTL and LTL model-checking and a user-friendly eclipse based front-end. Using model transformations to a Guarded Action Language (GAL) as intermediate format, ITS-tools can analyze third party (Uppaal, Spin, Divine...) specifications.