It recently came to my attention that Marineland Stealth and Stealth Pro aquarium heaters are currently being recalled because they may pose a potential risk of fire or laceration.
That's every Stealth heater since 2004 folks. :o
Links to information here: http://www.marineland.com/update.aspx (http://www.marineland.com/update.aspx)
(or here without pdf: http://www.marineland.com/images/marineland/update/MarinelandUpdate.pdf (http://www.marineland.com/images/marineland/update/MarinelandUpdate.pdf))
and here: http://www.bigalscanada.com/ML_Stealth_Heaters_Recall.pdf (http://www.bigalscanada.com/ML_Stealth_Heaters_Recall.pdf)
If you're like me and are currently running these in tanks, I'd humbly advise you to unplug them and head on out for a refund or exchange.
Remember: Safety first. Especially where electricity and water are concerned.