Desiccant

Sold in packets of 438 Bags which have 1 grams in each bag.

Bags are 20mm x 40 mm

Desiccant works by efficiently absorbing airborne moisture left inside the bag
after vacuum sealing, and captures moisture that manages to pass through
the bag material. Secure in a strong envelope of clean room compatible,
sulphur-free, Tyvek plastic, these desiccants keep your devices dry.
Meets the requirements of EIA 583 and MIL-D-3464, Types I&II.
Choose from eight sizes for just the right amount of protection.

One unit of desiccant is defined as the quantity having an adsorption capacity of 6 grams of water at 77° F (25 °C), at 40% Relative Humidity.
The desiccant Silica Gel (SG) for example is rated at 32 grams per unit.