Cheap And Discounts SN04-N Famous SN04N 4mm Approach Sensor NPN,3 wire,NO 6-30V DC Inductive Proximity Switch Wholesale. Buy Directly From Merchant Shenzhen Excellence IC Co. Ltd. Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.