D4 and D3 Bearing Boot
Bearing boot for the D4C SE (Special Edition), D4C, D3C, and D3A Rainbow vacuum.
The second image shows the old version (left) that has a smaller hole and can only be used on the D3A or D3C motor. If you have a mix of parts, do not use the old design on a D4C model Rainbow.
If you are unsure then all new inventory has the larger hole and allows for use on both the D3 series and D4 series.