Stages Left Side Power Meter Battery Door Description: This Stages Left Side Power Meter Battery Door replaces broken, worn, or missing battery doors found installed on left side versions of Stages Power Meters for Shimano non-drive crankarms. Features: Genuine Stages Replacement Parts Battery door for Shimano versions of Stages left side power meters Specifications: Color: Black Compatibility: Gen2. and Gen 3. Stages left side power meter arms