Specialized rib cage ii matte black ii one sizeThe Rib Cage II is not only a sleek, lightweight water bottle cage, but its also been designed to be fast in the wind. Of course, it also performs its primary task of holding tight to bottles dutifully, so you wont be losing bottles when the road gets rough. Accepts MTB SWAT Box (when used on compatible frames). Accepts SWAT Cage Mount Road or MTB Tool. Reinforced composite material improves durability without adding weight. SWAT compatible design