EDWARDS 284B-PL 194F (90C) Heat Detector The 280B-PL Series heat detectors offer fixed temperature or combination rate-of-rise and fixed temperature features. The heat detector is available with a white plastic reversible mounting plate. The plastic plate can be used for either flush or surface mounting. It includes a white skirt which covers the space between detector base and the mounting surface. Detector twists and locks onto mounting plate. Mounting plate may be surface mounted or mounted onto any 3 1/4 (83mm) or 4 (102mm) octagon box. Most orders shipped next business day with UPS or Purolator having 5 to 10 business day shipping and tracking.