Abstract: An insert liner is provided and is configured to be removably received in an inner cavity of a shoe. The elastomeric liner includes: a longitudinal portion: opposing first and second lateral portions; and opposing front and rear portions, wherein the longitudinal, lateral, front, and rear portions define a cavity having an opening configured below the opposing front and rear portions and configured to receive a user's foot; and a fastener coupled to at least the front portion and the rear portion of the liner while being bond free relative to a toe portion of the shoe, the front portion is configured to releasably adhere to the tongue portion to maintain the opening below an upper edge of at least one of the heel portion and the opposing sidewall portions and to define the opening configured to receive the user's foot.