The original inspiration for the GEL-SD LYTE™ shoes was inspired by an egg. Consisting of a shell and an inner membrane, the primary focus for the design was to protect the foot from outside environments. The concept of the shell is implicated onto the shoe's midsole and upper mold. This mold was initially formulated for both cushioning and a supportive foothold. The progressive tooling system is updated with FLYTEFOAM® PROPEL cushioning. This material helps create better comfort and a more energized feel underfoot.