1. Material: polyester 2. Capacity: about 2.5 liters 3. Multiple light-emitting strip design, safe travel at night 4. Exquisite sewing technology, soft flannel edging is more comfortable 5. Strong buckle, durable 6. Stretch quick-drying fabric, wear-resistant and tear-resistant 7. Multi-functional storage space, rationally divided warehouses, convenient for quick access to items during exercise 8. Multiple pockets on the chest for easy storage of mobile phones and supplies 9. Strap storage pocket with a key loop 10. Under-rib circumference: small 80-105 cm; large 90-110 cm 11. Weight: about 130 grams 12. Dimensions: Small 40x18x40cm, Large 45x25x42cm