DuPont Tyvek® Expandable Interoffice Envelope with String and Button Closure Almost impossible to rip or puncture Antistatic, water- and chemical-resistant, yet easy to write on Printed on two sides 100% recyclable 1-1/2" expansion. 100 envelopes per box. 10 x 13 WEIGHT: 7 lbs. SOLD AS: Box STOCK NUMBER: R9925