High-quality materials and waterproof function - The bicycle saddle bag is made of Oxford material, which is waterproof and scratch-resistant. The zipper adopts seam-sealed waterproof design to prevent rain from entering and keep the items dry and safe. [Avoid soaking the bag in water for a long time. ] Adjustable installation position and straps - There are multiple loops on the bag body, and you can remove the detachable straps to adjust its position on the back or front as needed. It comes with 3 adjustable fastening straps, 2 for the top tube and 1 for the upright tube. It can stay stable even on rugged roads and is easy to install. Suitable for most mountain bikes, road bikes and commuter bikes. Its size is 202027cm. Large Capacity and Large Opening - It can accommodate your daily necessities and cycling supplies, such as mobile phones, gloves, sunglasses, mini bike pumps and bicycle repair tools. The large zipper opening design is easy to take and put, and the non-slip zipper head can be easily grabbed even with winter gloves. Slim Design, Great Look - Made of premium materials, the front tube bag is durable, wear-resistant and does not deform. The slim body and its position under the top tube of the bike minimizes wind resistance and protects your legs from impact while riding. It is ultra-light and convenient for bike touring. Overall Excellence - Combining functionality, durability and convenience, this bike saddle bag is an ideal choice for cyclists who want to carry their essentials easily.