Weighing just under four ounces and designed for absolute comfort, the Salomon S Lab Sense Ultra Pack Set will carry everything you need during your ultra running event. Salomon's Motion Fit system is designed to give you complete mobility through stretch construction at the chest that follows your every move. The stretch sternum strap will expand while you breathe, and the shorter length of the pack keeps the weight off your hips and lower body, leaving you free to twist comfortably. The pack comes with two soft flasks that fit in the two front hydration pockets. One back compartment securely stows your energy gels, while a zippered front pocket gives your phone a secure place to stay in the event of an emergency. Comfortable enough to wear on its own or over a shirt, the system uses a blend of different mesh fabrics to not only enhance mobility, but to promote breathability so you don't have to sacrifice comfort to be well prepared for the long run ahead.