Cheap And Discounts Carbon Monoxide Alarm with 10-Year CO Sensor, CO Gas Detector with 10-Year Life Battery, CE EN 50291, VC21, Black, 2-PACK Wholesale. Buy Directly From Merchant Shop1104279766 Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.