Model 711 and 521LX(T) Hardware Update
June 10, 2002
Beginning in June 2002, all Model 711 Single Point Zone Expanders and 521LX and 521LXT Smoke Detectors are being manufactured with updated hardware: 711 level D, 521LX(T) level C.
To view this Technical Update in a pdf format, visit https://dmp.com/downloads/Tu-0254.pdf.