This is a set of 16 A4-sized thick paper envelopes for 580 yen. Dimensions are 32.2 x 22.8 cm, suitable for Yu-Packet, Nekopos, and Click Post. They come with sealing stickers (for closing) and opening zippers (to easily open the envelope by pulling), making them convenient. Although they are slightly thinner, they are made to be durable. I personally use these for shipping regularly. (I accidentally ordered one digit too many, so I'm selling them at a bargain price.) Shipping will be done by wrapping them in an OPP bag and then putting them in a kraft envelope, and sending them via Click Post, etc.