Captive Ball Cars are smooth running, efficient and easier to load and unload from CB track • Used with 1631 or E2730 for 3:1 purchase • Recirculating ball bearing travelers move freely under non-vertical loads and have a low-profile design • The fully machined bearing races provide smooth operation and the captive bearing feature takes the hassle out of installation and maintenance • The "old" 1500 Series Midrange cars will work on the new track but not the other way around