Vicki
These O-Rings fit over the tube the footrest rotates on and provides a "friction" fit so that the foot plates do not rotate back down. These allow the foot plate to be moved without having a release lever of any kind. They are designed for use on our MRI Wheelchairs and also fit MRI Wheelchairs sol by other companies. These fit the 7/8" tube the footrest rotates on.
We do not have any knowledge of them fitting Non-MRI Wheelchairs such as DRIVE, Invacare, Karman, Meyra, Pride or any other Non-MRI Wheelchair.