These is our new Highline Dolly, equipped with 3 inch wheels, also known as a Speeder or Skate. This dolly is designed for use by Stunts, Special Effects and Grips or Camera. This is used to support a load traveling along a synthetic rope or cable stretched between two points. This small 3 inch is compact and light; 11.25in(286mm)x 4.15in(105mm) x 1.875in(48mm)4.4lbs (2kg). They are made of Black Anodized 6061T6 aluminum. The wheels have double row sealed high speed bearings retained by snap rings, so they are replaceable. The bearings are rated at 2600 lbs dynamic and 1600 lbs static. The 11000 rpm speed rating on the 1.7' tread of the wheel comes out to 55 miles per hour. Available with wheels for 1/2 inch (13mm), 5/8 inch (16mm) and 3/4 inch (19mm) synthetic rope. Two captive pin shackles are included; these will fit into the ends of the bottom of the dolly. For camera use we suggest that you use jacketed synthetic rope.