Alarm Sound Level: 85dB at 1m, Tolerance: ±3%LEL, Visual Warning: Green: System is on / Electric connection Yellow: Fault / Sensor has lost efficacy, Alarm Set Point: 5%LEL, Material: ABS Plastic, Related Humidity: ≤95% RH, Audible Warning: Speaker(voice alarm), Red: Alarm / Gas Leakage, Power Consumption: <3W, Warm-up Time: 3 minutes(Regular) 10 seconds(Customized), Operating Temperature: 0℃ ~ +55℃, Sensor Type: Catalytic, Detected Flammable Gases: Natural gas(methane) / LPG(liquefied petroleum gas), Operating Voltage: AC110V/220V/230V or DC12V/24V, Area of Usage: Households, Response Time: ≤30 seconds, Dimension: 132*91*39mm, Apparatus Type: Standalone Type / Linkage Type / Networking Type. You can create price alert here, copy coupons and view price history. You probably want to know what is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
1. ($9.99): BGe825b3
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): Terence, BGKAMAR20, MVC8SPRING, 8BGwbg2204, BG33ecef, BGa87b17, BG5a0905, BGa1f035, BGe9545f, BG5c5e29, BG8ReviTrage, BGeaf456, BG00c906
(there’s a little possibility that old coupon will work)
Price history and price alert
Check out price history chart (for all/most countries) for Combustible Natural Gas Detector. The lowest price was: $9.99.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).