These are REPRODUCTION Silent knight keys for 58xx series panels, etc. These are COMPATBLE with ALL Silent Knight panels, annunciators, test switches, etc. which use the black plastic key. These are 3D printed from high strength black PETG. They are just as strong if not stronger than the original keys. Modern 3D printers are able to match the tolerances of the original key fairly well. Please reach out with any concerns about quality or if you need a replacement key. Thanks!
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