HDB 630 vs Momentum 4 Pads

Does anyone know if the Momentum 4 pads are identical to HDB 630 pads in every way? I know that the mounting points are fully compatible but not sure on the thickness, cushioning materials, seal etc.

When searching "hdb 630" on the official sennheiser spare parts page, I only see replacement pads listed as Momentum 4's (code: 700210), will these change the sound signature/quality of the HDB 630? (I don't need to replace my HDB 630 pads yet but just for future reference).

Thanks