When sourcing glass reed switches, you must prioritize Contact Rating (Watts), Switching Voltage (VDC/VAC), and Switching Current (Amps). For high-reliability industrial use, ensure the Sensitivity (measured in Ampere-Turns, AT) aligns with your magnetic trigger; a lower AT range (e.g., 10-15 AT) indicates higher sensitivity. Additionally, verify the Contact Resistance, which should typically be below 100mΩ to ensure signal integrity, and the Insulation Resistance, which should exceed 10^9 ohms to prevent leakage.