Material: synthetic. Synthetic material is a collective name for artificial materials that do not come from animals and nature. Outer material partly of mesh. Mesh is a perforated net that lets air through. Used for the shoes to be able to breathe to the maximum. Outsole in synthetic material. Cycling shoes have two advantages over ordinary shoes: the sole is hard and gives you power down into the pedal, and the shoes have room for blocks underneath (the blocks are adapted to the type of pedal you use). There are 3 types of cycling shoes: Racing shoes, which have an extra hard sole but are still light and have an aerodynamic design. The blocks for racing shoes are called SPD SL. MTB shoes, with a rough sole that is slightly softer so that you can walk shorter distances with them. The blocks for MTB shoes are called SPD. Spinning shoes, which are very similar to MTB shoes but adapted for indoor use and with more airy materials on the top. The blocks for spinning shoes are called SPD. SPD-SL is a pedal system developed by Shimano to get better power transmission down into the pedal. SPD-SL is adapted for the racing bike where you want optimal transmission of power from foot to bike. The blocks adapted for this type of pedals are suitable for very stiff shoes that do not fit to walk in.