This bulk pack of Quality Park Dab-N-Seal envelope moistener bottles makes it easy to seal thousands of envelopes quickly. Adhesive formula glues as it moistens to securely seal up to 1,500 envelopes per bottle. Patented spill-proof spring-valve applicator won't clog, so envelope production keeps rolling along. Lab-tested formula: this non-toxic, non-flammable and water-soluble adhesive cleans up with a quick wipe and water. Ideal for office work including labels, stamps and mailers or for paper crafts and art projects. The only way to seal! Fast-drying nonflammable, non-toxic formula conforms to ASTM D-4236. Spring-valve applicator won't leak even when tipped over. This bulk pack is ideal for the fast-moving offices or busy schools! Keep one at every desk and never lick an envelope again! The 12-pack seals a whopping 18,000 envelopes.