Cordura 305d polyester thread / has a strength against friction, tearing, and abrasion. L-VENT treatment on the back (3 layers) / "Allows water vapor to pass through" and is made of breathable and waterproof material that has a water pressure resistance of over 78.6 ft (20,000 mm). Front pocket, side zip pocket, waist harness pocket with seam tape processing; Prevents water from entering through the sewing section; Back layer provides storage space for PC and other PCs; Brushed material and thick cushioning material provide excellent protection for your electronic devices. By adding cushioning material to the shoulder pad, etc. and using stretch material on the back to reduce the burden on your shoulders. Waist bag for cell phone, cards and small items / waist bag is detachable with Velcro. The main body material is made of waterproof fabric with 3 layers, but there may be cases where seams have been applied to the seams tape.