tiantie001
https://www.tiantiebuilding.com/products/viscous-damper.html
Viscous damper(or seismic damper) from Tiantie is a kind of damping device that is composed of a high-strength metal cylinder, piston, guide rod, sealing element, and viscous damping fluid. When the cylinder and the piston move each other, a throttling damping force caused by the movement of the built-in viscous damping fluid can absorb and consume the impact energy of the earthquake on the building structure to the maximum extent and alleviate the impact and damage caused by the earthquake to the building structure.