Abstract: Improved adjustable midsole for footwear, with the midsole comprising an airtight, evacuable capsule containing granules and air, whereby the midsole is moldable to the shape of the wearer's foot for improved support and comfort, with the midsole retaining said shape through evacuation of air from the capsule. The improved midsole further comprises sipes such as slits or channels integrated into the midsole to improve flexibility.