Bests & Worsts Reviews from Amazon

I have been using these for 10 years. They say that they probably need replaced by ten years, so I ordered several more. They do a great job of pulling extra moisture out of my safes. I did figure out that I can replace the silica beads in the old units. I did not want to do it until I got the new units in place. But there are 4 screws in the back of the unit. You can loosen them and pop off the little door on the side, or take screw all the way out (beads will go everywhere, use a bucket), Dump the beads and order some from EBay. I replaced all the beads in all 3 of my old ones for $16. They are easy to put back together and after you refill the units, you can jimmy the door back in place. It has snap tabs on it, so you can pop the door back in. Each unit holds about 320 grams of beads.