Double-Hill Electronic Lock Company was founded in 1986 selling low cost locks and was certified ISO9002 in 1999. Today, Double-Hill manufactures solid brass door hardware, marketing a complete line of high-end decorative hardware, which includes handle sets, knobs, levers and dead bolts for residential and light commercial applications. Electronic handle sets round out the line for the high quality hotel/motel industry. Double-Hill is the top selling hardware company in China. Door hardware is the first thing that visitors touch and feel when entering your home. Double-Hill entry door hardware set the tone for the rest of the house. With SDH Hardware, you get the security you need without the sacrifice of style or functionality.