Sieve sleeve, ETA-approved for the use of injection mortars in perforated or hollow stone, suitable for M8 threaded ends. You drill into the hollow stone with a diameter of 13, inject two-thirds of the sieve sleeve with injection mortar, place the sieve sleeve in the drill hole and insert the threaded rod with a rotating movement within the prescribed gel time. Mortar will be forced out through the meshes of the sieve sleeve, creating a plug in the hollow chambers of the stone that hardens there