SECURE: Clasp closure plus gummed closure for reliability, security and ease of mind that your contents will securely stay closed in the envelope DOUBLE SEAL DESIGN -double prong metal clasps with reinforced eyelets and heavily gummed flaps ensure the envelope stays closed and durability REUSABLE-Great value, each box comes with 100 6x9 clasp envelopes that can be reused multiple times for a bargain VERSATILE: Get these brown kraft envelopes in various sizes, depending on your needs. MULTI-PURPOSE: Use these Brown Kraft envelopes as office envelopes, interoffice envelopes, storage of documents, etc.