Many bulk materials are extracted from silos or other containers by vacuum conveying and transported through pipes. The question of how the detected metal residues can be rejected from these vacuum systems is just as important as proper metal detection. The extractor combines multiple advantages for this purpose. It has a tight-fitting changeover flap that safely rejects metal residues and functions without any loss of positive/negative pressure in the conveyor line. As a second special feature, the material passes through a cyclone, which results in a very small size because the distance between metal sensor and flap is artificially increased to a necessary level. To also ensure that all particles are properly ejected from the material flow, the entire cyclone and the switch are purged with compressed air on every ejection procedure. The metal is detected by proven metal sensors and Digital2, MESEP or M-Pulse2 evaluation electronics.