sachet of silica gel crystals. it is a desiccant. it adsorbs and holds water vapor

absorbent absorber adsorb air attention away bacteria bag bags ball balls caution cautions crystal crystals deoxidizer desiccant dioxide dry free gel humidity moist moisture mold new pack packet packets packs pouch pouches recharge sachet sachets sand sands saturated silica silicon small spheres throw tiny unsaturated vapor vapour water wet white