Unisex The North Face Flight Training Hydration Pack. Size Medium Color TNF Black. Volume: 610 in³ (10 liters). Water bottles retract quickly with a simple leash system. Breathable, cooling fabric. Layered pocketing with secure-zip pocket for streamlined organization. Large back pocket fits jackets and other large items and closes easily without having to take off the pack. Pocket above back hem fits trekking poles to secure them while you’re running. 360-degree reflectivity enhances visibility. Minimal, easy-to-use, adjustable harness. Minimalist whistle included for security and to meet race regulations. Proprietary water bottles included. Body: 60 g/m² woven Cordura® nylon ripstop with non-PFC durable water-repellent (non-PFC DWR) finish. Pockets: 80 g/m² nylon, elastane with FlashDryT. Dimensions: 16.75″ x 6.5″ x 17 (42.5 cm x 16.5 cm x 43.2 cm). Avg Weight: XS – 6.98 oz (198 g) / S – 6.98 oz (198 g) / M – 6.98 oz (198 g) / L – 7.05 oz (200 g).