This efficient desiccant begins it's work by absorbing air borne moisture left inside the bag when you've finished vacuum packaging, then it captures moisture that manages to pass through the bag material. Can be baked and re-used. - Secured in a strong envelope of either clean room compatible, sulphur-free Tyvek or economical Kraft Paper, SCC desiccant helps keep your devices dry, even through unexpected shipping delays or longer than anticipated storage time.