The product is a set of 400 W2 self-seal double window security envelopes designed for W2 forms. These envelopes provide a secure and convenient way to mail W2 forms, ensuring they are protected from tampering or theft. The double window design allows for easy insertion and sealing of the forms, while the self-seal feature provides added security. Ideal for businesses and individuals needing to send W2 forms, these envelopes offer both protection and ease of use in the packaging and shipping process.