Ride easy with the VPD System Knee. It’s highly flexible and provides exceptional protection, making it a great option for any type of mountain biking. It features an extreme ventilation system so you don’t get overheated when riding and is covered with abrasion-resistant outer fabric for increased durability. VPD System combines the lightweight breathability of VPD Air with the protection level of VPD 2.0. It wraps around your body when you’re moving, then hardens and absorbs impact upon contact, helping to minimize injury so you can ride (and fall) with confidence.