Hi, sir,It is nice to write to you. This is mubarak from Oman. I am interested in placing your gas detector, smoke detector fire alarm on the market.May I know more information about product such as:Model Number,Usage,Do you have any quality assurance certificates? I am interesting to buy 20 pcs. Looking forward to hearing from you.With Best RegardsmubarakDiamond Ocean This Message is from mobile Show More