Kraft Tab Locking Stayflats® #5 – 9 3⁄4 x 12 1⁄4″ DIMENSIONS:Dimensions in the chart do not include flap.The number in the chart listed in () is the industry standard # for that size mailer.Usable: 9 1/4 x 12″Based on contents no more than 1/4″ thick.THICKNESS:.036″ RECYCLING:RecyclableRecycled Content: 100%Post-consumer: 70%Industrial strength with economical kraft savings.Heavy board keeps items flat during shipping.Will not bend or crush.Tab lock for mailing or shipping. 100 Pieces is 25lbs.