When sourcing, prioritize manikins with anatomical accuracy, including a realistic chest cavity, rib cage, and sternum notch. Ensure the model features head-tilt/chin-lift capabilities to simulate airway opening. For feedback, look for units equipped with audible 'clicker' mechanisms or LED light indicators that validate correct compression depth (typically 5-6 cm) and rate (100-120 bpm). The skin should be made of high-grade PVC or TPE materials that are durable, easy to clean, and resistant to staining from face shields.