Stainless steel building door each door switch corresponds to a household extension, in fact, the power switch, the switch is pressed, the power is turned on households. Extension was electric, extension inside the musical sound. After the extension hook toggle switch is switched to the electric amplifier circuit section can be an intercom. Therefore, this doorbell into the family has six lines, in addition to a different outer ring, the other is parallel. When do you hook home intercom listen stainless steel security door fittings, as you can hear the conversation. Yongkang St. Chang Industry and Trade Co., Ltd. Stainless steel building door craft exquisite production, quality, price concessions, welcome customers and friends to buy. St. Chang Industry and Trade remind you in the purchase of the security door when the following points: (3) Qualified Security door plate thickness should be 2mm above the door frame, door thickness of 20mm or more, you should check the weight of the door, should normally be more than 40kg, and by removing the cat's eye, the doorbell box or lock the door handles and other ways to check the internal structure of the door plate thickness should be 1.0mm or more, within a few root reinforcing steel grade stainless steel security door, the door body front and rear panels connected together organically, and enhance the overall strength of the door, the door preferably with asbestos with fire, thermal insulation, sound insulation material functions as a filler stainless steel security door handles, hand percussion door body issued a "pound" sound, consumer hands to open and close doors should be flexible. Buy safe gated Yong Kang Shengchang industry and trade, product qualities rich, luxurious atmosphere, imported copper plate, abrasion-resistant, corrosion-resistant stainless steel security door price, reputation first St. Chang Industry and Trade, Jiangsu stainless steel security door by Yongkang St. Chang Ltd. provided. Yongkang St. Chang Ltd. (www.shengchangco.com/about/) Zhejiang Jinhua, household goods inventory leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customers needs. Trade and Industry Leadership at St. Chang staff warmly welcome all inquiries negotiations to create ShengChang better future for industry and trade.