Clarks Propose Spire Slip-On Shoes Leather Bendables construction incorporates a system of flex grooves in the outsole for a flexible feel. OrthoLite foam footbed offers long-lasting cushioning that's lightweight. Soft leather or suede upper with slip-on styling allows for easy on / off. Thermoplastic rubber outsole provides traction for a confident stride. Fabric lining feels soft against the skin.