Ixs flow zipknee guard With the Flow ZIP knee guard, iXS provides super thin, light and comfortable knee protectors. According to its name the Flow ZIP features an elastic zip FlexZip which simplifies put them on and off. Developed with mountain bike legend Hans Rey, pads are super compact to fit any backpack. The integrated Xmatter padding concept provides high impact absorption and protection. With the Flow ZIP we introduce product properties like exchangeable padding, structurally improved AeroMesh of newest generation offering a higher level of comfort and structural strength. X-matter - Flexible Viscoelastic polymer absorbs forces without hindering range of motion. The open cell compound is engineered to withstand multiple impacts in the same region while retaining its shock absorbing properties. Aero mesh - Lightweight 3D performance mesh, optimized for breathability and moisture wicking. Sizes (Circumference Leg Width Above Knee â€“ centimeter): Kids Small â€“ 30-32 Kids Medium â€“ 32-34 Kids Large â€“ 34-36 X-Small â€“ 36-38 Small â€“ 38-40 Medium â€“ 40-42 Large â€“ 42-44 X-Large â€“ 44-46 XX-Large â€“ 46-48 Care Instructions: Machine wash/Hand wash program 20 celcius Remove protective pad before washing. Do not tumble dry, clean with chemicals or bleach.