this is the US Military 2 Unit size that is sufficient for a 5 gallon pail, to remove all of the residual moisture. EXCELLENT FOR STORAGE OF ANYTHING THAT WILL DEGRADE VIA MOISTURE!! FOOD/ELECTRICAL PARTS/TOOLS/GUNS/AMMO/ YOU NAME IT!!!! packet measures 2" x 4" and about 1/4" thick OR GO TO MY EBAY STORE FOR A 20/PAK, OR 50/PAK AT A GREAT SAVINGS!!!!!