Affordable hydration day pack for hiking or walking with included water bladder. Organization & pockets Maximum back airflow Multiple configurations Elevate your hikes with our Oasis 18L and 22L hydration-compatible backpacks. Ample front and side pockets make room for everything from first aid kits to food in addition to the 2L (Oasis 18L) or 3L (Oasis 22L) hydration bladder. Don’t let your gear hold you back: this adventure-ready backpack is designed for comfort and efficiency with body-mapping mesh for maximum air flow, adjustable chest and waist straps, and padded, contoured shoulder straps. Make your bag your own with two sizes and multiple colors to choose from. Hike happy.