Additional maintenance operations. ADJUSTABLE TIGHTENER 2.9 Q4 V6 is a high-quality accessory belt tensioner bearing part designed to fit your vehicle perfectly. Identified by OE reference 670050605, this part offers a seamless fit and dependable performance. Crafted from durable materials made for long-term use, this brand-new Original FIAT GROUP Equipment ensures your vehicle remains in peak condition and performs exactly as intended.