TA-15 This kit includes mounting adapters for both front and rear Transceivers on K and R series BMWs (up to 2004) with a 12mm drive-shaft pivot. The adapters are designed for easy installation on existing hardware. No drilling or modification is required. Rear adapter mounts on 12mm Hex pivot bolt of the drive-shaft Front adapter is a 10mm modified caliper bolt There is a 5mm stainless steel dowel pin press-fit in the adapter which is used to mount the Transceivers facing the wheel. A nominal air gap of 1/2" (12mm) or less allows the short range communication between the Transceiver and the Wheel Sensor. Each adapter includes detailed step-by-step instructions.