Haversack bag that originally came with the PDF-D or GP-5 Russian gas masks. They have Russian writing on the inside. The one pocket smaller bag that is made for the PDF-D measures 6.5 inches tall, 7.5 inches wide, and 4.5 inches deep. The GP-5 3 pocket bag has 2 side pockets that are 5 inches tall, 4 inches wide, and 1.5 inches deep. The main compartment is 10 inches tall, 5 inches wide, and 4.5 inches deep. The adjustable single strap can go as long as 20 inches.