https://www.5startools.com/tools-1/4-gallons-premium-blue-indicating-silica-gel- desiccant-beads Contains 100% Blue Beads 4 Gallon >> Net Weight 30 LBS Blue beads turn from Dark Blue to Light Pink when absorb moisture and saturated. These beads contain 'COBALT CHLORIDE' which may pose health risk and environmental issues. Our blue beads contain only 0.005% cobalt chloride. Beads can be Reactivated by Placing in the Oven for 0.5-2 hours at 200-250F Or Microwave for About 10 Minutes at DEFROST. Don't use over 250F in the Oven. Depending on beads' condition, they may take shorter than the recommended time. Please check the beads' color periodically. GOOD FOR Air Compressors, Paint Booths, Gun Moisture Control and Tank Dries Tel : 773-225-5979 KEN