Strobel Sock or Strobel board
What is a strobel bottom of a sneaker? The Strobel is the fabric or non-woven material used to finish the bottom of a shoe upper. The worker uses a Strobel machine to make a Strobel stitch to attach the Strobel board to the upper. It was invented by a guy named Strobel. Almost all athletic shoes made by Nike and Adidas are made by the strobel process.