Front / Rear Idler. Final Drive Reduction Assembly. If you’re looking for top-quality undercarriage parts at the best possible prices, you’ve come to the right place. Cut out the middle man and deal direct with. DIEX-Undercarriage carries cutting-edge undercarriage parts that perfectly fit any machine model made by top brands in the industry. Bottom Track Roller Specifications. Be 100% sure you’re ordering the correct part for your machine. There are two types of it. Please show us your old bottom roller before you place order. And it’s better to give us its size. So we could help you verify it 100% clear. It is a durable undercarriage replacement part for your excavator. It was designed and manufactured to exact OEM specifications using a high-quality, high-strength steel. It will provide long-lasting and dependable performance even if you operate in the most extreme conditions. All these transport timeliness don’t apply to remote districts. So we could help you solve the problem well. Our goal has always been to grow a long lasting business, one customer at a time. We strive to bring you the best customer service with quality parts.