When sourcing biological sample transport boxes, prioritize triple-layer packaging systems (primary receptacle, secondary packaging, and outer packaging). The box must feature high-density polyurethane (PU) insulation to maintain stable temperatures (e.g., 2-8°C, -20°C, or -70°C). Ensure the inner liner is leak-proof and easy to disinfect, typically made of medical-grade polypropylene (PP). For high-value samples, look for integrated real-time temperature and GPS tracking modules to monitor environmental fluctuations during transit.