The Stage Knee guard offers mid-range trail protection in a packable package. D3O (R) is used for impact protection. D3O (R) is soft and flexible to keep the guards comfortable while riding, but on impact, the D3O (R) material hardens to disperse the energy for protection. Slip on a pair and head out to the bike park in confidence. Troy Lee Stage Knee Guard | Black | X/2X | Christy Sports