The Lockdown Vault Dehumidifier Rod -This allows the warm air to circulate throughout the safe on a continual basis, thus eliminating humidity, mildew, and condensation. All of which are dangerous to your expensive firearm collection. Removes moisture from gun safe interior Mounting brackets includedDries approx. 100 cubic ft. (12 inch ) or 200 cubic ft. (18 inch) Easy install quick plug attachment, 110vProtects firearm investment Guards against rust