PAC GUARD™400 PAC GUARD™ 400 is a non-destructive leak detection system designed for production line quality control, and package development applications. Emphasizing ease of operation, the Pac Guard 400 can detect weak heat seals, gross leaks, or small pin holes in finished products within seconds. Ideal applications include sterile medical supplies, food packaging, and pharmaceutical packaging. This portable system can be used to test blister packs, foil pouches, plastic pouches, thermoformed cups, bottles, boxes, and small packages. Testing works best with dry products where some headspace exists. An optional CO2 pressure chamber is also available.