They are the same mailers as used by Amazon for mailing out their books, and the original Bukwrap brand. All our book wraps contain 'peel & seal' strips with permanent strong adhesive for easy and efficient application and use. A pack of 25 x medium C2 size book wraps, also known as cardboard mailers. The size of these quality wraps is 260x175mm (length x width), and the depth is adjustable between 0-70mm. Perfect for multiple DVD's and smaller books, these are extremely high quality cardboard mailers manufactured in the UK. The C2 size of mailers fits large letter for royal mail purposes, making them extremely cost efficient. The weight of each mailer is 79g.