"Diameter: 29 mm. Length of Rod: 71mm Diameter of mounting holes: 3 mm Material: brass; aluminum. Cups with hinged rod are suitable for sealing pull-open doors. This product is attached to the door, then must be made a hole in the wall. When the door closes, the rod moves into the hole, and then is covered with plasticine and sealed with a metal stamp. Today, hinged-rod sealing devices are in demand in many organizations. "