BikeFit Leg Length Shims (LL Shims) are used to compensate for leg length discrepancies with SPD cleats. Our 3 mm LL Shim is made in the USA of high-density plastic to conform to the curve of the sole of the shoe. Features: Screws are included Made of high-density plastic to conform to the curve of the sole of the shoe, 3 mm thick The leg length shims are used to compensate for leg length discrepancies One SPD LL Shim is the maximum recommended per shoe Includes: (1) SPD/Mountain Bike Leg Length Shim (2) 14mm Hex Screws (2) 16mm Hex Screws (2) SPD Cleat Wedges (which can be "stacked" to create an additional 1 mm of height) Installation Instruction Sheet (also available under the "Resources" tab)