Super abrasion behavior Extremely robust and up to 200% longer lifespan compared to plastic knee sliders thanks to the raw material wood (hornbeam) Low resistance on the road Super well processed - the Velcro is glued over the entire surface and sewn on the edges Rain sliders - extra thick (between 2.5 and 3cm thick) milled grooves to drain the water, so the sander reaches the asphalt and does not float on the water. Made in Germany for optimal grip and comfort, the sander is anatomically pre-shaped. Here is a pair (2 pieces) of wooden knee sanders in the extra thick rain version