Thank you for viewing. This is a new, unused Ziploc bag purchased from Takuhai Coop, 50 sheets. It was a bit pricey, so I think it's more durable than the 100-yen store ones. It has a double zipper. The size is 20.5 x 20.5 cm. I purchased it 3 months ago. I took it out of the outer box, but it's new and unused. Thank you for your consideration. m(_ _)m