When sourcing gang switches, prioritize high-quality PC (polycarbonate) materials for the outer shell, as they offer superior flame retardancy and impact resistance. Internally, ensure the contact points are made of silver alloy, which provides excellent conductivity and prevents electrical arcing. For the internal bridge, phosphor bronze components are preferred due to their high elasticity and fatigue resistance, ensuring the switch maintains a firm grip over thousands of cycles. Always verify that the product has passed endurance tests of at least 40,000 switching cycles.