The SCS 2PLDES150 Desiccant in Tyvek Pouch, 2 Unit, 150/Pail begins working by absorbing airborne moisture left inside the bag after vacuum packaging, capturing moisture that manages to pass through the bag material. Secured in a strong pouch of sulphur-free, non-woven Tyvek, desiccant helps keep sensitive devices dry, even through unexpected shipping delays or longer than anticipated storage time.