Are the suits that firefighters wear fire resist?
click on the subcategory in list at top of page (about 2/3 of the way down) called IN PERMANENT CELLS to at least see some suppliers for pendant trays, cabachon settings, etc, etc. My Jewelry page (under J in the alphabetical nav. bar) should also have links for regular online jewlery suppliers like Fire Mountain Gems, etc. HTH, Diane B.
Batteries should be replaced once per year. Generally you should schedule to do it at a time-change so you remember to do it each year. The detectors themselves should be replaced (depending on the type) every five (5) to seven (7) years. Ionizaton detectors have generally a longer life than photo-cell detectors as they are less sensitive to dirt or dust in the environment. The radioactive element (Americium 241) has a half-life of about 432 years, so radioactive decay is not the issue. Note that some hard-wired detectors may be cleaned and thereby have an indefinite service-life. So, check what you have. Note also that some units are dated with a service-life - check those too.
