SPECIAL SHAPE and UPGRADE STRAPS:saddle bag with wave cushion provides inside shock resistant protection if fell out. RAINPROOF:Waterproof fabric with taped zipper for rain. Do not soak this seat bag in the water for a long time( stitches are not waterproof ) EASY TO INSTALL:2 stickup straps and a rubber buckle simplify mount system. Moreover , it keeps bag securely attach to seat post NIGHT VISIBILITY:Reflective strap around the seat bag to increase night visibility while night cycling. Taillight hook compact space on the seat post ( Taillight doesn't include in the package ) Colour:black+orange Material:Composite waterproof material + pearl cotton Package Contents: 1 x Bike Seat Bag Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.