MC5 are suspension caster forks designed for use on lightweight low-profile sports wheelchairs. Available in a choice of light-, standard-, or heavy-duty models these aircraft aluminum forks retrofit most sports chairs and feature polymer shock absorbers that reduce the effect of vibration on the wheelchair user. They also reduce the chance of the user being pitched from the chair when the front wheels encounter obstacles; each wheel travels independently over the obstacle. These forks offer a choice of axel positions and accommodate wheels from Rollerblade through five-inch casters (not included). The polymer retains shock absorbing capability for three to five years and may be replaced when needed. OPTIONS: Caster wheels and tires. DIMENSIONS: The forks are 1.5 inches wide. In the lower axel position they are 4.5 inches high and in the upper axel position, they are 4 inches high. CAPACITY: The light-duty model has a capacity of 40 to 150 pounds. The standard model accommodates 120 to 220 pounds. The heavy-duty model has a capacity of 200 to 300 pounds. WEIGHT: 0.57 pounds per fork. COLOR: Black or silver.