Xlab Super Wing is a mounting system and does not include: saddle, post, bottle cages, x-nut, x-straps, or other accessories. Includes: Carbon Wing, All Hardware, Upper and lower strap sets, Detailed Instruction. Xlab uses the latest carbon fibre composite with a special lay-up and resins to provide the toughest carbon carrier on the market with no twisting like other carbon hydration carriers. Without hardware, the Xlab Carbon Wing weighs only 55 grams. The Xlab Carbon Wing is designed for 7mm metal saddle rails only.