These are the same high-quality Primo Aluminum Casters that you are used to but we have added our high-performance Wheelchair Bearings 608-2RS bearings to them.
Designed for those who want the ultimate smooth ride, these Ultra Light Aluminum Wheels feature an attractive aluminum hub and highly resilient, soft but solid urethane tire that will never go flat and help to minimize energy loss and absorb vibration.
To improve pivot ability, the contact surface is spherical and features an arched tread design. This WIDE model allows the wheels to maintain higher flotation by better distributing downward pressure, which helps keep the user from sinking into the carpet, soft ground, etc
Specifications:
Size: 4" x 1", 4" x 1-1/2", 5" x 1-1/2",6" x 1-1/2"
Bearing I.D. 5/16" 608-RS
Bearings included: Yes
Hub width: 1", 1-1/2"
Tire profile: Rounded
Airless: Yes