When sourcing electrical knife switches, you must prioritize Rated Current (A) and Rated Voltage (V) to ensure they match your power system requirements. Key specifications include insulation voltage (Ui), short-time withstand current (Icw), and the number of poles (Single-pole, Double-pole, or Triple-pole). For heavy-duty applications, ensure the base is made of flame-retardant materials like BMC or high-grade ceramics, and the conducting parts are 99.9% pure copper with silver or tin plating to minimize contact resistance and prevent oxidation.