The SM 7446 is a high-precision A/C compressor clutch pulley specifically engineered for the BMW E90 (3 Series). Designed for the high-efficiency Denso-type (typically 6SEU / 7SEU series) compressors found in the 320i petrol and 320d diesel variants, this pulley is built to meet BMW’s strict requirements for harmonic balance and near-silent operation. It ensures that the premium cabin experience is maintained without any mechanical intrusion or vibration.