The product is a pack of 100 12×15.5 Poly Mailers Envelopes by the brand Smart Seal. These self-seal shipping bags are made in the United States and have a thickness of 2 mil. The size of the envelopes is 12″ x 15.5″, making them ideal for various shipping and mailing needs. The unit quantity is 100, ensuring that you have an ample supply for your business or personal use.