Two WC-1 Wheel Chocks Linked with Chain that fits 60-141 lb Rail. For Exposed Rail Features: Easy to Apply for Temporary Blocking of All Types of Rail Cars Designed for Use on Grades of Less than 1% All Models Fit 60-141 lbs. (27-64 kg) Rail Fit Wheel Sizes: 30", 33", 36", 40", 42" MODEL # DESCRIPTION