Baleaf Bicycle Strap-On Saddle Seat Bag Made from highly durable 1680D Oxford Fabric Velcro strap and snap-on buckles offers easy attachment and removal 3M reflective material and taillight hanger enhanced safety in low light Large main opening allows access to your riding essentials, keys, wallet, cellphone and tools Dimensions: 7" L x 3.5" W x 3.9" H (Expandable version)