Transporter Wheels from Cua Claws were developed to increase camera footage in slippery PVC pipes. They are available in four sizes and are made of stamped 16-gauge steel. The wheels are furnace brazed to attach a coating of 16-grit carbide chips for traction. The method of attaching the carbide ensures a long life for the wheels. They fit most popular cameras and do not need to be modified. The wheels are pre-drilled for application. Sizes include 2.5 inch, 4.0 inch narrow, 4.0 inch wide and 5.5 inch wide. The company can also regrit all makes of steel transport wheels. 714/697-8697; www.cuaclaws.com.