Heavyweight Tyvek Envelopes are super strong, moisture-resistant and tear-resistant. Tyvek expansion is ideal for superior protection for mailing bulky items. These 18 lb. plain envelopes feature an open-end design for easy insertion of documents. Convenient peel-to-seal closure requires no moisture to close.

Expansion - 12" Width x 15 1/2" Length - 4" Gusset - Peel & Seal - Tyvek - 50 / Box - White