The 900 gram silica gel unit protects 66 cubic feet of enclosed space. This is a larger version of our 450 gram unit. It protects larger areas and requires less frequent reactivation. The 3″ x 6″ x 8″ carton has a built-in corrugated indicator that turns from blue to pink to signal the need for reactivation. Reactivates in any conventional oven. Ideal protection for larger safes, cabinets, vaults, or closets.