Pro Short Liner Featuring SmartFlex(TM) Stretch: Form-fitting and lightweight protection that hardens on impact. DESIGN & DETAILS: Body-mapped, impact absorbing SmartFlex(TM) pads offer form-fitting and lightweight protection that is flexible during play and hardens on impact The SmartFlex(TM) Stretch pad is created to vent as it bends reducing unnecessary heat build up Fits like a second skin while protecting hips and tailbone Machine Washable