The document provides information on RWM caster's wheel model numbering system. It lists the different types of wheels available categorized by material like cast iron, steel, nylon, urethane etc. It also explains the codes used in the model number to indicate wheel diameter, width, axle diameter and optional features like bearings, lubrication and durometer. For example, the model number UI R 08 20 08 70D stands for urethane on iron wheel with 8" diameter, 2" width, 1/2" axle and optional 70D durometer.