I purchased two of these 1500D Silica Gel items. One was for a larger sized Pelican case and another for a small 'dry box'. They have worked out great and I've already recharged the one from the Pelican case in the oven (3 hours at 300 degrees). As I value the item contained within the Pelican case I think this preventative item is well worth the cost. I would certainly recommend it to anyone with sensitive equipment. If you can't clean off your equipment right after use it seems to buy you some time before you get to it.
Pros: Well, its advertised feature: absorbing moisture.
Cons: Recharge time in the oven.
This review was written in the old system and had content requirements that are different than reviews written today.