- Expandable Capacity: This motorcycle tail bag expands from 20 to 35 liters (14.6"L x 11.8"W x 9.5"H standard size; 14.6"L x 11.8"W x 15.7"H expanded), providing ample storage for clothes, shoes, helmets, tablets, and lunches. The universal strap mount ensures compatibility with most motorcycles. - Easy Installation: Designed with individual straps and quick-release plastic buckles, this bag is simple to install and remove. Follow these three steps: 1) Open the cushion and attach the straps, 2) Cover the cushion, 3) Secure the helmet bag and tighten the straps. - Water-Resistant Design: Made from durable waterproof EVA and 600D Oxford fabric, this bag protects your belongings from unexpected rain. An included rain cover provides additional protection against wet conditions, ensuring your items stay dry regardless of the weather. - Multifunctional Backpack: Features a removable, comfortable, and breathable mesh double shoulder strap, along with a top handle for easy carrying when not on the bike. Quickly transform the bag into a helmet bag, messenger bag, handbag, or backpack to meet your diverse needs. - Practical Use Scenarios: Great for weekend rides, it allows you to store extra gear without cluttering your motorcycle. Ideal for commuters, this bag accommodates essentials for work or school. Use it for day trips to carry snacks and equipment securely. This motorcycle tail bag combines convenience and durability, making it an essential accessory for riders looking for reliable storage solutions on the go.