Eva-Dry claims 500 cubic feet of protection with this self contained unit.  Works just like the other desiccant product but with the addition of a built in heater unit allowing the unit to be recharged simply by plugging it in to a wall outlet without having to fire up the kitchen oven to bake it out.  This unit is NOT plugged in during use.  Great for gun safes.

Eva-Dry claims 333 cubic feet of protection with this self contained unit.  Works just like the other desiccant product but with the addition of a built in heater unit allowing the unit to be recharged simply by plugging it in to a wall outlet without having to fire up the kitchen oven to bake it out.  This unit is NOT plugged in during use.  Great for gun safes.

Indicates humidity levels.  Blue spots turn pink as the humidity level reaches or exceeds the indicated level.  Color returns to blue when humidity level drops below.  Keeps on going.... and no batteries!  Measures 1 9/16" x 4 3/4".

Check the humidity level inside your Mono Vault without opening the lid.  No need to expose your desicant to a fresh batch of air.  You desicant lasts longer!  Bulkhead style mounting.  Just drill a 0.72" (23/32") hole.  Seals hand tight with supplied gasket, fiber retainer, and nut.  Indicates 20-30-40% humidity.  Body made of Acrylonitrite-styrene (high impact plastic).  Install in the center of the lid or in a recessed flat.  Made in USA.

Installed FREE with Mono Vault Purchase.  Just indicate your desire in the memo line at checkout.  All factory installations of the Vault Check are in the center of the lid.