亚洲小视频-亚洲小视频网站-亚洲小视频在线-亚洲小视频在线播放-三级全黄裸体-三级日本黄色片

This product is a kind of damper dependent with velocity,and includes cylinder,piston,fluid,piston rod,sealing materials,and etc.It can decrease bridges’ damage and subsequent mechanical displacement when earthquake occurs.Products comply with:JG/T 209-2012 Dampers for vibration energy dissipation of buildings.