This sack is fully enclosed with a draw string liner and a four way cinching top flap. Made of 430 Packcloth. The CSS works great with our 3 Day Assault Pack (603D00), Special Operations Medical Pack (60MP00), Phoenix Pack (60PH00) and our Patrol Pack (60PP00). Spacious design with a secure top. Dimensions: 29 x 9 Wt: 7 oz