The QKD Demo Setup is a terrestrial, open-frame demonstration system designed for learning, teaching, and hands-on experimentation in quantum technologies. The setup includes eight silicon single-photon detectors (Si SPDs), a bulk free-space optical system, and two time taggers for coincidence and correlation measurements. The optical components are fully mountable and demountable, allowing users to perform optical alignment, configuration changes, and experimental tuning. With no enclosure, the system provides direct access to all optical and electronic elements, making it well suited for practical training in quantum optics, quantum sensing, and quantum key distribution concepts. The platform is intended for universities, training labs, and users seeking practical experience with real quantum hardware.