This review is more for the people at ICON than for the product.
I had alot of problems with carbon monoixde alarm going off on site. Our local nimrod safety supply house (who should be nameless Grainger!) had no clue what they were talking about let alone what they sold us!
Found out one site we have ALOT of hydrogen and it was playing havoc with our sensor. These guys suggested to switched to a hydrogen resistant sensor and it works perfectly now! No more shitting my pants from false alarms!