Castaldo Quick-Sil is a two-part room temperature vulcanizing (RTV) silicone-molding putty that produces tough, strong, long-lasting production jewelry molds for lost wax casting with 0% shrinkage. Castaldo Quick-Sil is safe, non-hazardous and non-toxic and does not produce unpleasant fumes or odors. It is easy to use - merely mix equal parts of part A and part B by hand. There is no need to measure precisely or vacuum in order to achieve optimum results. No need for vulcanizing but it does work best if the product is clamped under pressure like in a vise or an unheated mold press. Castaldo Quick-Sil comes with precise detailed instructions for use. Packaged in two containers, part A and part B, weighing a total of 2.2 lbs. .- No careful measuring .- No messy liquids .- No 12-24 hour wait for finished molds .- No vulcanizer needed .- No release sprays -- it's self-lubricating .- Package 2 part (2 Lb.) .- Vulcanization temperature Room Temperature .- Working time: 1 to 2 minutes. .- Cure time: Approximately 15 minute. .- Shrinkage: 0.0%. - MADE IN USA