don't use gas saver net
Ok, this gas saver net (or energy saving ring or whatever they call it) is not safe for use.
Earlier this month, the Bureau of Standards, Metrology & Inspection, Taiwan ordered a recall of all such device. It was tested that the burning efficiency after using is lower than without the device, and the carbon monoxide concentration exceeded their national approved level.
In 2009, 2 women in Hong Kong died of carbon monoxide poisoning. Their kitchen was found with the device used on the gas cooker. Test conducted by Hong Kong's Consumer Council found carbon monoxide concentration increase 40 times after using the device.
Anyway, it came to my attention that a particular online shop is using my previous post word for word, image for image (then put their own watermark) to sell this gas saver net. That's the kind of originality some entrepreneurs-wannabe have. That's besides the point.
So if you find your kitchen using such device, please exercise your judgement.