I'll start by saying this dryer is almost solid plastic.  It feels flimsy but does stay upright, even with shoes or boots on it.  It does not have a switch, so the only way to turn it on or off is plug it in or unplug it.  There is no fan, just gentle heat that rises through the tubes and into the shoes, so it is completely silent.  The base does not get hot at all, so it does not seem to be much of a fire hazard.

That said, it is very effective.  My adolescent is often offending me and others with the odiferous nature of his feet and footwear.  I bought him two pairs of sneakers and he alternates them daily, but I still occasionally have to bleach them to rid them of the odor.  I bought this, attached it to a 24-hour timer like one you would use for lighting, and it is set to turn on in the evening.  He puts his shoes on this thing and two hours later, the timer shuts it off.  No more odor.  Problem solved.

Even when I have washed the shoes, it only took about 6 hours to dry them completely from a sopping wet condition.  It is not as fast as a clothes dryer for that purpose, but it is certainly effective and does not shrink the leather.