Every SLR owner should have a dry box..without one be prepare to fork out your fortune for costly repair cost if your lens is infected with fungus..:)
This dry box is a fully digital dry box with humidifier control. I set it to 43%
This dry box is just nice if you have 2 long lens a big body and another spare space for you battery grip of flash unit.
so far the digital display always shows me a variance of 1% +- of the value that i have set for humidity.
I highly recommend this unit.