3 Packs Combination Gas Carbon Monoxide Detectors, Plug In, Easy To Install Product Features ?Hembisen Plug in Combination Gas Carbon Monoxide Detectors ? This is an upgraded 2-in-1 gas and carbon monoxide detector with plug-and-play, digital display and 85 dB alarm. ?2-in-1 Gas CO Sensors?Adopt catalytic combustion sensor and electrochemical sensor for sharper sense of smell and accurate. ?Power Saving Mode Design?When there is no dangerous gas around, the combination gas and carbon monoxide detector will automatically turn on the power saving mode and only show green light. ?Digital Display 85dB Alarm?When combustible gas or carbon monoxide gas concentration is detected to reach the default value, the combination gas and carbon monoxide detector will display LEL or PPM, and at the same time, it will emit 85dB alarm sound. ?2-in-1 Detection Function?Can detect carbon monoxide gas and combustible gas; combustible gases include natural gas,LNG, LPG, propane, methane and etc ?Applications?Combination gas carbon monoxide detectors is suitable for home, restaurant, apartment, office, hotel, petroleum plant, gas station, camper van, etc. Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!