Our Fusion blocks are 100% handmade in Germany, and use the highest quality walnut wood sandwiched between two layers of cork. This finish gives a bit more weight to the blocks, as well as a hard surface for your fingers to rebalance on, while also making use of the non-slip cork surface at the bottom, and the smooth cork feel for the top of your hands. Dimensions Small - 13.5cm x 9cm x 6cm Large - 13.5cm x 10cm x 6cm