This Packman Saddle Pack features a saddle rail rack and adjustable side compression straps to increase stability and minimise rattle during rides.The pack includes a roll-top waterproof carrier that helps protect contents and allows for flexible storage capacity.Velcro fasteners provides a straightforward and secure attachment onto the seat post.. Specification: Material: 420D / 600D high density fabric (water repellent and abrasion resistant),250D Tarpaulin (IPX5 waterproof),Stainless steel (rack),Size: 48 x 18 x 16 cm / 19 x 7 x 6.5\",Capacity: 8L (waterproof carrier),Includes 9 mm carbon rail mounts,Maximum load : 2.3 kg,Minimum clearance from saddle rail to wheel : 20 cm/8\",.