Shimano 2014 Unzen Cycling Hydration Pack - 6 Liters - UNZEN06 (Blue) Helmet Holder:This versatile clip allows you to securely attach your helmet to the bag. Eyewear Holder:When you take off your eyewear, you can hang it in this dedicated holder. Hydration:Hydration compatible bag is equipped with a dedicated section for securely holding the included hydration system. Reservoir CompressionThis function helps improve stability by stopping water from sloshing about when levels run low in the hydration pack. Light Attachment Loop:A rear-mounting light-attachment loop works in tandem with reflective elements to provide peace of mind when you find yourself caught in traffic after dusk.